Mystery, Command

Mystery. Of sorts. This crime was not sufficiently interesting for him. But something was up, because Greg Lestrade hadn't called in the SOCOs yet. They'd normally be impatiently waiting for him to be done with it already. Instead, only the detective inspector's best team – Sally Donovan and her two brightest constables – were here. Despite the small numbers, though, they were still droning on as he crouched beside the body. Why couldn't they keep quiet? What was the point of repeating inanities to one another?

Trust Donovan to be the one whose voice reached his ears most clearly, muttering to Lestrade: "This is bizarre. Someone enters his flat this morning, slices his throat open, breaks into his safe and takes everything in it, but leaves an entire gold bar jammed into his mouth?"

Very good, Donovan. Gold star for you. Now shut up.

Sherlock blocked out the background voices as he scrutinised the victim lying face up on the floor of the sleek kitchen in this Chelsea flat. Afternoon sunlight streamed through the windows, illuminating the white-and-steel décor marred by the mess on the pale stone tiles. Mid-30s, gym-toned, manicured and buffed to within an inch of his life before someone had destroyed his polished perfection by slashing his throat, severing the trachea and both carotid arteries, as John confirmed. Blood had soaked through the entire upper half of his green silk dressing gown.

From his mouth protruded a bar of gold that probably weighed about one kilogram.

Nothing of interest here. Apart from a couple of psychological details which someone else could sort out.

"Why are we here?" Sherlock grumbled.

"Because there's a dead man with a gold bar sticking out of his mouth?" John asked in his best "perhaps you haven't noticed" voice.

"No, why are we here?" Sherlock repeated, standing up and turning around to glare at the DI standing just inside the kitchen with Donovan. "There's no mystery, Lestrade. It's obvious."

"As I said when you arrived, this wasn't my idea," Lestrade reminded him with a good-humoured smile. "I knew it wouldn't be an interesting-enough crime scene to keep you amused for more than four minutes."

"Three minutes and thirty-seven seconds," Sherlock shot back.

"Whose idea was it, then?" John asked Lestrade, confused. "And Sherlock, for the thousandth time, your definition of 'obvious' isn't necessarily the same as anyone else's."

"If His Finickiness beside you had stopped to listen instead of grandly sweeping past me as if I were the doorman, he wouldn't have to ask," Lestrade told John. "I had a phone call…"

That moment, Lestrade's phone buzzed in his hand.

"… and here he is," Lestrade finished cheerily.

"You mean…" John began, as understanding dawned. "… Mycroft?"

Of course.

"Sherlock – before you go," Lestrade stopped him. "Just tell me if what I've seen matches up with what you have – the pictures, the magazine on the coffee table, the gold shavings on the dining table, the hidden security camera?"

Sherlock studied Lestrade for a moment, then nodded and added: "Also, literary references are etched on the gold bar."

"That, I may need pointers on later," Lestrade admitted before sending Sherlock and John out with a toss of his head. "Go on. Go see what he wants."

Sherlock strode out of the flat and walked downstairs to the street, John half a step behind him. Mycroft's Jaguar was parked by the pavement, Anthea standing beside it with a smile so flawlessly bland, it was practically a work of art. She opened the rear passenger door for them, Sherlock nodded to her, John flashed her a strained grin, and they slid out of the autumn chill into the warmth of the compartment. The door closed behind them, and Sherlock was in Mycroft's presence again.

He hadn't seen him since their dinner at Marcini's two weeks ago. A text he'd sent 12 days back, asking if they could meet, went unanswered for five hours before the response came: I'm out of the country. I'll contact you when I return.

Texts, e-mail messages and phone calls after that were met with silence. After Sherlock broke into Mycroft's house, Anthea had rung to say that Mr Holmes would get in touch after his trip, and Sherlock should call her in an emergency.

He felt a discomfiting mix of relief that Mycroft had returned, seemingly unharmed, and was sitting beside him now, and frustration that he had totally ignored him for two fucking weeks.

Then Sherlock saw the scarf. It rested over his waistcoat but beneath his jacket, one finely woven edge just visible under his lapels and collar, the deep earthy hue with plum undertones sitting well against his predominantly olive-toned suit, cream shirt and sapphire-blue tie with discreet gold markings.

The sight of Mycroft wearing his gift shut him up just long enough to give his brother and John the opportunity to set the tone for their meeting.

"John, Sherlock," Mycroft greeted them politely as if he'd only just seen them yesterday.

"Hello, Mycroft. So it was you who told Lestrade to call us in," John remarked in classic stating-the-obvious fashion. (Which Sherlock had come to appreciate – only on occasion, mind you – as a socially acceptable lead-in to certain conversations requiring civility.)

"I requested it, yes."

"Why?" Sherlock asked.

Between Sherlock and Mycroft, that single-word question prodded at more than one matter, but now was not the time or place for other layers of the query.

"I need you to retrieve something that was taken by the person who entered Henry Carter's home and killed him," Mycroft said. "It has become a matter of some urgency."

"Lestrade's team should have no trouble snaring the killer in a few days," Sherlock pointed out. "Your people can retrieve whatever it is then. You don't need me."

"I need you to get hold of the items," Mycroft stated. "I have every faith in Detective Inspector Lestrade. However, I can't risk inadvertent exposure of sensitive materials that mean nothing to the CID, but are of import to people in significant positions."

"What are these items?"

"Letters," Mycroft replied. "Good old-fashioned ink-and-paper letters."

"What's in them?"

"Might you both have been too young to remember a quarter-century-old case that began when a Chinese politician's daughter eloped with an American diplomat?"

"That rings a bell," John said. "I vaguely recall that she killed their children, then herself, when he left her."

"That's right," Mycroft confirmed.

"What does it have to do with this Henry Carter and his post-mortem gold accessory?" Sherlock asked.

"Narrating the entire history of it may seem like a morbid retelling of The House That Jack Built," Mycroft said, his mood somewhere between grim and amused. "Except that instead of the dog that worried the cat that killed the rat that ate the malt, I'll be going on about the English Casanova who cheated the Frenchwoman who married the American man who abandoned the Chinese woman who killed her children."

Sherlock groaned. "To the point, please."

"Meet me halfway," Mycroft proposed. "I'll give details first, then I'll summarise. Twenty-five years ago, Zhu Yu, the daughter of an elite member of the Chinese Communist Party, was a student in Paris when she fell in love with Luke Patterson, a young attaché with the US embassy in France. In the early 1990s, it would have been hard for a citizen of the People's Republic of China with a politically prominent father to marry an American with a mission in Europe. Much resistance would have come from both sides. Patterson's contacts helped him marry Zhu Yu secretly in France, then he left his job, she abandoned her studies, and they assumed new identities. According to the sketchy intelligence sources Britain had in China at the time, her father raged about how his daughter and the American had run away with all the money meant for her studies."

"Something of the flavour of 'my ducats and my daughter' in that," Sherlock remarked.

"Been re-reading your Shakespeare, have you?" Mycroft asked with an approving smile. "You're not far off the mark. Rumour had it that the girl had not only stolen her father's money, but also gold and jade items of cultural and historical value which he had illegally taken out of China at some point in the past and hidden in his Paris house. Word in the underworld was that he would hunt them down to recover his treasure. However, he was hampered by the eyes of his own party on him; he couldn't even admit to knowing of any such gold and jade artifacts. His daughter was also said to have sent cryptic warnings to him that she would give the CCP evidence of his crimes if anything happened to her or Patterson. Confirmation of such corruption would have meant a death sentence in China."

"But things went bad for her, didn't they?" John asked.

Mycroft nodded. "As far as we know, they lived off her stolen wealth in Marseille. But in less than four years, during which time they had two children, Patterson fell for a Frenchwoman, Isabelle Mollard. He abandoned Zhu Yu, expecting her to put up with his having a mistress. Socially isolated, deeply depressed and bitter, Zhu Yu snapped. She smothered her children – a toddler and an infant – before killing herself with an overdose of drugs."

"Except for her dying, that has Medea all over it," Sherlock muttered.

"Shall I make you a gift of the books on Greek mythology that you removed from my library without asking my leave?" Mycroft's smile was the tiniest bit unsettling. "I'm delighted you're going through them so thoroughly. I'm sure that if I'd mentioned Medea last year, you wouldn't have recognised her name any more readily than Margaret Thatcher's."

"I'll return them when I'm done, Mycroft," Sherlock grumbled, wishing he was alone with him so he could just clear up… some matters.

"Back to Patterson. The fool realised the danger he was in with his wife and children dead. Her father, Zhu Jianguo, might now try harder to hunt him down. Patterson thus sought protection from European intelligence agencies. In exchange, he offered information his wife's twin brother had sent her just before she died. It seems that after years of hiding, she'd initiated contact with her brother when Patterson left her. Her brother seemed to have hoped she could use the documents as a bargaining chip – they revealed how Chinese spies had stolen what was considered, at the time, valuable details about new internet and systems-infiltration technology being developed by British, French and American organisations."

"Zhu Yu's brother had access to state secrets?" John asked.

"Both siblings seemed adept at obtaining things they shouldn't have been able to," Mycroft said. "But when Zhu Yu died, the information was left in her husband's hands, and he flogged it to protect himself and Mollard. I won't name names, but certain agents of ours contacted by Patterson then were foolish enough to enter into fairly open correspondence with him. Mollard didn't trust email, which in the mid-1990s was still relatively new to the general population in many countries. So they exchanged conventional letters, in which Patterson alluded to the gold and jade, seeking assurance that he wouldn't have to part with it. Our British idiots actually replied that he could keep the treasure; they only wanted details of the technological secrets stolen by the Chinese spies."

Sherlock looked hard at Mycroft. "And these idiots who wrote to Patterson are still around?"

"Not only that, they have risen to high positions – which is why I won't name names," Mycroft said. "They're prime examples of goldfish who scale the career ladder because of their laughable incompetence rather than the reverse. Thank God I was still at university then and not yet involved with our intelligence services – there's no excuse for such stupidity."

"Why have the letters become a problem now?" John asked.

"From this point, I will summarise heavily," Mycroft said. "In brief: British and French intelligence agencies took the information they needed, cooperated to give Patterson and Mollard a new life elsewhere in France, then British intelligence washed its hands of the case. But Zhu Jianguo was charged with corruption in China in 2000. He admitted to illegally exporting valuable antiques which his daughter had in turn stolen from him. The Chinese government, which was cracking down on the unsanctioned removal of cultural and historic treasures from their country, contacted various Western governments that they thought might have knowledge of the case. Britain was among the countries China sought cooperation from to locate and return the items."

"And the idiots in charge of intelligence at the time denied knowledge of the treasure," Sherlock finished the sentence for his brother.

"Exactly," Mycroft affirmed. "If the letters are exposed now, our government, which at this time needs all the international goodwill and openness to trade deals it can get, will risk damaging its relationship with China for having lied about this years ago. Some people whose names are on those letters are among the ones I previously mentioned as putting pressure on me with regard to Eurus."

"And they've now gone to you, cap in hand, for help," Sherlock said.

Mycroft nodded. "If we can retrieve the letters before anyone sees them, it may kill more than two birds with one stone. The idiots would be in my debt, and I could make them back off. John, I take it that Sherlock has told you of the problems I'm facing at work?"

John nodded. "I'll help in any way I can. But what does the dead man lying in his kitchen have to do with any of this?"

"Henry Carter was a love cheat who pretended to be an IT entrepreneur or whatever he could get away with claiming to be. In reality, he tricked rich, isolated women into falling in love with him before making off with their wealth. Patterson left Mollard everything when he died in a car accident in 1999. She'd been widowed for 16 years when Carter came into her life. After he stole almost everything she had, breaking her heart, she killed herself at the age of 48 in the Cote d'Azur in January this year. There's no sign that Carter knew about her history. He only knew she had a lot of cash and jewellery, and a safe full of antique treasures. Perhaps if he'd only taken Mollard's things, he might not have met this violent end. Unfortunately, he also took a puzzle box and other personal items that had belonged to Zhu Yu."

"A puzzle box?" Sherlock asked. "Oh. That decorative cylindrical object in the photographs was a puzzle box?"

"What decorative cylindrical object? What photographs?" John asked, befuddled.

"John," Sherlock sighed. "Did you not notice how house-proud Carter was? The framed pictures in the hallway of how his home had evolved over the years? Or the two-month-old magazine lying open on his coffee table with a spread featuring his flat's interior décor?"

"I… can't say I did," John confessed, deflated.

"Two of the photos were recently framed – however carefully all the frames were polished, the oxidation on those two differed. And glossy print magazines take three to four months from shoots to publication. Which means the pictures shot in his flat for the story were probably taken about half a year ago. The magazine and the two newer framed pictures show his mantelpiece holding an elaborately carved cylindrical wooden item that doesn't appear in the older pictures. So it must have come into his possession little more than six months ago. Now it's missing from the mantelpiece – the flat's well dusted, but I could see a faint outline of where an object had sat for months. It must have been removed this morning."

Mycroft inclined his head. "Zhu Yu's brother, Zhu Zheng, who was not implicated in his father's trial in 2000, moved to Europe in China's new era of relative personal freedom. It appears that he's been trying for years to find out what happened to Patterson and his sister's personal effects. The magazine featuring the one-of-a-kind rosewood puzzle box gave him his lead. He entered Carter's home, killed him and retrieved his sister's personal property."

"It's a bit of a long shot," John noted. "That he would find the one magazine with a picture of his sister's puzzle box."

"That's not quite how it transpired," Mycroft replied. "Remember I told you British intelligence had washed its hands of Patterson and Mollard? We had. But we also have agents who are, shall we say, on intimate terms with friendly agents in countries we regard as neutral, or good partners. We do not forbid such liaisons as long as our people understand we must vet everything they share with their foreign partners. A side benefit is that we do receive helpful information from them as well, on cold or peripheral cases. One of our agents is close to a Belgian agent, who coincidentally made contact with Isabelle Mollard several years ago on an unrelated case. Mollard came to think of this Belgian as a harmless but important business associate. Last Christmas, when she'd fought with Carter over something, she spent an evening alone with the Belgian, utterly drunk, boasting about how her late husband had old secrets that could topple governments. Among the things she showed off was Zhu Yu's puzzle box. She told the Belgian that her husband had known how to open the box but she didn't. It was too valuable for her to smash, but she knew Patterson had kept letters in it after his first wife died. Among the names she said she'd seen years ago on these letters were those of the idiots who are now begging for my help."

"When happened then?" Sherlock asked.

"Our Belgian friend told our agent all this. Unfortunately, before MI6 could retrieve the letters, Carter stole Mollard's money and valuables – including the puzzle box – and vanished, breaking her heart. He'd been wooing her under an assumed name, so when Mollard reached out to her Belgian friend for sympathy, she could tell him nothing about Carter's true identity, other than that she was sure he was British. Her suicide hardly made it easier to dig Carter up. At this stage, the case had not crossed my desk, because it had seemed a straightforward MI6 matter. It wasn't until two days ago that a random Facebook user in France posted snapshots from a private party held last year. One showed Mollard with Carter – who did not appear to know his picture had been taken. With that, MI6 finally identified him. By noon today, they had his address."

"But by the time they got there, he was dead," John murmured. "That was when they started begging for your help."

"I had my people alert the CID to the murder, and I put DI Lestrade on the case, privately warning him that he must keep his team very small and trustworthy, call you in first, and keep out everyone else until you were done."

"How did you connect Zhu Zheng to this?" John asked.

"Street camera footage recorded this morning. A man we've identified as Zhu Zheng entered this building at 6am. Zhu has been a businessman in Paris for years now, growing his own network to trace anything Patterson had left behind. Although Mollard herself changed her name long ago, there's every chance he recognised her picture when news reports of her death after being deceived in love were uploaded on French news sites. Zhu Yu probably sent her brother photos of Mollard long ago when lamenting her husband's betrayal, and Mollard was a striking beauty who, by all accounts, had retained her looks. That set Zhu on the same trail after Carter that our services were on, but he had a lucky break that we didn't. Zhu once engaged a British freelance photographer for one of his business projects, and this fellow was among the people he'd sent the Facebook photo to, asking if anybody recognised the man in it."

Sherlock saw where this was going: "And the photographer went 'Oh, hey, isn't that the guy whose flat I shot for the recent issue of Perfect Homes? Funny bloke, happy to have his place snapped, but not himself. Want to meet him? Here's where he lives.'"

"Not so crudely, but in sum, yes. We learnt this barely an hour ago. Once we'd identified Zhu from the streetcam footage, we hacked into his accounts and found that e-mail exchange with the photographer."

"But Carter had nothing to do with Zhu Yu's death," John pointed out. "Why would Zhu Zheng kill him and stuff a gold bar into his mouth? That seems highly personal. Why not just break into his flat when he wasn't there to get his sister's things back?"

"Remember the literary references I mentioned to Lestrade?" Sherlock asked. "The gold bar has, etched on it, names of two female characters from A Dream of Red Mansions who were let down by the men they loved. Perhaps because of what happened to his sister, Zhu hated men who preyed on, betrayed, or caused the deaths of the women who loved them."

"Very good, Sherlock," Mycroft purred. "Brushing up on Cao Xueqin as well, are we?"

Sherlock coloured at the low register of Mycroft's purr, and hoped John didn't notice. Ignoring the comment, he explained: "The names I could see included three in Chinese ideograms, "林黛玉" (Lin Daiyu), "尤二姐" (You Erjie) and "朱玉" (Zhu Yu), and one in the Roman alphabet, "Isabelle". I'm speculating, but I think the psychological essence of it is that Zhu left the gold bar behind as a statement that he had killed Carter not for his valuables, but for being the final link in the chain of events that had begun 25 years ago with his sister falling for a man who proved unworthy of her love. Although he should have hated Mollard for being the third party in his sister's marriage, he seems to have ultimately perceived her as yet another woman who had suffered because the man she loved had betrayed her. He saw Carter as the cause of her heartbreak and suicide. A life for a life. He killed Carter and added Isabelle's name to the gold bar – he coolly sat there in that house after killing him and breaking into his safe, took one of the old Chinese gold bars from the cache his father had illegally exported, used something sharp to etch the names into it, which is why there are gold shavings on the dining table, and stuffed the bar into Carter's mouth. This also alluded to how, in the novel, You Erjie swallowed a sizeable piece of gold to kill herself after the man who'd taken her as his second wife failed to protect her from his vindictive first wife. Zhu was shoving all that misery back at Carter, in a sense."

"Well… I guess it doesn't not make sense," John said thoughtfully, before asking curiously: "You can read Chinese? Since when?"

"All right," Mycroft cut in. "Listen to me. This is what's going to happen: My agents now have eyes on Zhu. And my team is combing through hours of security and streetcam footage to confirm where he's put the things he took from Carter. Once we pinpoint the location of the puzzle box, the CID will arrest Zhu, and your job will begin. I need you, because none of our intelligence units can be seen or suspected to have anything to do with the items. The CID too should be perceived to be investigating Zhu only for killing Carter and committing theft. There must be no indication that the Yard currently knows what significance the items have. I will tell Lestrade what he needs to know to arrest Zhu, and he will question him for as long as possible before charging him with the crimes the CID already has footage of him committing – because Carter's sitting room has a concealed security cam. This will give you time to work on the puzzle box. However, we cannot be certain that Chinese intelligence hasn't paid anyone in the police services to report matters of interest to them, so you cannot be seen fiddling with the box. Wherever we find the box to be, I will have Lestrade smuggle you into that location. His team will secure the area with you inside, unseen. You will remain there until you have opened it and retrieved the letters without damaging the box or leaving any sign that it has been tampered with."

"How do you know Zhu Zheng hasn't already opened it and removed its contents?" John asked.

"Because of another thing Mollard revealed to the Belgian agent during her drunken rant. She said that Patterson and Zhu Yu had been the only two people in the world who knew how to open the box. It was custom-made for Zhu Yu by her late mother, who gave it to her so that she would have – and I quote Mollard – 'at least one place that your brother cannot get to'. From what we've gathered, Zhu Zheng had long been in love with his own sister, and their parents had sent her to Paris while barring her brother from leaving China, to separate the twins. How to open the box was one thing Zhu Yu never shared with her brother, so that, as her mother hoped, she could have a private spot to keep her own secrets in."

"Good Lord," John muttered. "This story just gets more bizarre."

"Go back to Lestrade now, wait for me to brief him on a secured line, and for my team to pinpoint where Zhu has put the box. Let Lestrade arrest Zhu and get you secretly to the box, then you can work on it. John, I need you to protect Sherlock. Are you armed?"

"Not today."

"Take this," Mycroft handed him a fabric pouch which evidently held a revolver. "Use it if anyone gets past Lestrade's team securing your eventual location and tries to hurt Sherlock."

"Right," John said, slipping the pouch into the inner pocket of his coat.

"Okay," Sherlock said with a nod at the same time.

His immediate acquiescence prompted John to cast an odd look between Sherlock and Mycroft. "What, no arguments? No caustic remarks?"

"John, I need to talk to Mycroft," Sherlock said. "Would you go back up and tell Lestrade he can bring in the SOCOs now? I don't need to crawl around that flat any more."

"Sure," John said, opening the door on his side and climbing out of the car. "Please don't kill each other. Should Anthea get in to babysit?"

"Go away, John," Sherlock intoned.

He laughed and shut the door after him, leaving them alone. Sherlock kept his face turned towards the window of the door John had left by, while Mycroft looked out of the window beside him.

"So is this to be one of my 'Labours of Hercules'?" Sherlock asked. "If I pull it off, do I get to claim my reward?"

He felt the full weight of the three seconds of tense silence Mycroft allowed to bear down on him before his brother asked: "You do know, don't you, that Hercules' labours were carried out as penance for killing his wife and children? And there was no reward for him at the end other than the completion of his atonement?"

"Well, I imagine atonement fits quite nicely into this too," Sherlock said softly.

Mycroft was silent for another weighty five seconds before suggesting: "Perhaps you were thinking of Perseus."

"Perhaps I was," Sherlock said, trying to stop a smile from forming on his face. "So, if I slay this Cetus of a puzzle box for you, do I get to claim my Andromeda?"

Yet another dramatic silence sat between them for several seconds, ending with Mycroft saying very cautiously: "I hope you're under no illusion that your Andromeda is a virgin, a beauty and a bride. That would be asking rather too much in this day and age."

Sherlock, unable to hold it in any more, let out a tiny snort of laughter as he referenced the old jibe Irene Adler had once made: "I thought I was supposed to be the virgin."

In his peripheral vision, he saw Mycroft touch the knuckles of one gloved hand briefly to his lips as he disguised his own huff of laughter as a clearing of his throat, followed by the remark: "That must explain why you always seem to be on the verge of being sacrificed for one thing or another."

Mycroft's remark had a touch of humour, but also guilt, and Sherlock didn't want to hear that, so he quickly replied: "This particular virgin is capable of biting back harder than the monsters, you know."

Mycroft gave in to a low chuckle and observed: "Virgins certainly aren't what they used to be."

"And beauty is in the eye of the beholder. I think I like the look of my Andromeda. So, will I get to claim my prize?"

"Go and slay that Cetus of a puzzle box first. Afterwards, you can seriously consider whether you really want to claim your prize," Mycroft answered.

"And to ask if my prize is willing to be claimed," Sherlock added, reading the unspoken thought.

"Indeed. Prizes aren't what they used to be either, as you know."

"All right. I'll go. I'll see you very soon with the letters," he said, turning his head for the first time since they'd been left alone to look properly at Mycroft.

"Don't make promises you may not be able to keep," Mycroft warned, likewise turning to face him.

"Fine. I'll do my best. Oh, but I've just realised – we're wrong about the puzzle box being the Cetus I have to slay. The puzzle box is the Gorgon I have to decapitate so I can return with the head that will petrify the Cetus of your enemies."

"I begin to suspect that your curly head full of twisting snakes will be quite enough to petrify them all by itself," Mycroft commented.

"Good. Then whatever happens I can enter into negotiations for a prize that may or may not wish to be claimed. Feisty prize, is it? Or… would frosty prize be more pertinent to our specific context?"

"Good God," Mycroft shuddered, but his cheeks betrayed a touch of pink. "Get out of here before your cringe-inducing analogies turn me to stone."

Sherlock bit down again on the smile threatening to erupt, and left Mycroft's car.

Later, when the call came and Lestrade made his move, Sherlock found himself concealed in a Soho hotel suite where Zhu had locked up everything he'd taken from Carter's flat. There was the puzzle box – a thing of beauty, about 30cm tall and 20cm in diameter, so elaborately carved it was hard to know where to start appreciating the numerous birds, flowers and symbols shaped on it, and intricately assembled with more than twenty moving parts that might or might not align to let you in.

He first photographed it from every angle to ensure that he would put it back as he'd found it. It was a devilish contraption – not a basic puzzle cylinder that only required you to rotate the sections until the internal mechanism lined up to let you separate the segments. This had all that, as well as sliding catches and tabs. Sliding the wrong catch or raising the wrong tab in a combination that might otherwise get you somewhere would lock down an adjacent segment and keep the box closed.

"John, this will take a while," Sherlock warned his partner.

"Do what you have to. Rosie's fine with Mrs Hudson tonight; I'm not going anywhere," John assured him.

The crime no longer had so much as a scrap of mystery left in it, yet it was now worth every bit of Sherlock's interest and time as he bent his mental powers to working out how to open the box without damaging it.

Command. He had always been the master, ordering underlings on missions, commissioning champions to execute his plans, manipulating them like game pieces for his country. Sherlock had been the most brilliant and unpredictable knight he had wielded to keep this kingdom safe.

His brother had never gone forth quietly. Biting sarcasm and petulance always peppered the preamble before he charged off and unleashed chaos on the world. But that had not happened today. Never before had Sherlock accepted a task from Mycroft so willingly. Never had he expressed so plainly that he would readily do it because he was doing it for Mycroft's sake.

It gave him an unsettling sensation. Echoes of their incredibly embarrassing exchange in the car fluttered in his belly, making him feel adrift in his usual role as the commander who watched and coordinated all through the monstrous Argus of his network of camera-eyes. Sherlock's double-layered words, like an infernal spell, had left Mycroft disorientated, as if someone had shoved him onstage without prior warning into a performance in which he was suddenly expected to play the damsel in distress.

A damsel masquerading as the god of war, watching her knight go into battle for her.

Ridiculous. And here came that terrifying flutter in his belly again.

Anthea must have sensed something off about him, for she told him to leave the command centre and go home to rest as he hadn't slept since stepping off the plane last night. When he ignored her, she insisted, assuring him that she would keep him apprised of every development.

So he went home and forced himself to sleep, knowing he would need mental sharpness later. He managed four hours – more than adequate – before an update woke him at 3.30am. Sherlock and John were leaving the hotel, and Lestrade's team was driving them to Baker Street. Sherlock, Anthea said, looked ready to crash. She didn't think he would resurface before daybreak.

Mycroft knew better.

True enough, Anthea swiftly provided a fresh update, and at 4.30am, Sherlock rang Mycroft's doorbell, actually waiting patiently to be admitted instead of pulling his usual stunt of breaking into the house.

When Mycroft let him in, he held out a Loro Piana shopping bag. "Here's the paraphernalia your scarf came with, as promised two weeks ago," he slurred, not from alcohol or drugs, but sheer fatigue. "Getting the contents separately from the packaging is novel, isn't it?"

"You always have to do things differently," Mycroft remarked.

"Well, it does give the giver another opportunity to add something else worth having to all the wrapping."

Mycroft lifted the boutique box out of its carrier and opened it to find the letters from two decades ago.

"Well done, Sherlock," he breathed. "Thank you for the present. It's perfect."

"Go lock up your Gorgon's head safely," Sherlock told him. "Can I use your shower?"

Mycroft eyed him, assessing how mentally worn he was from solving the puzzle.

"Yes," he finally agreed, when he determined that his brother was in no shape to engage in strenuous argument with him for at least the next five hours. "The spare bathrobes are…"

"Yeah, I know where everything is," Sherlock mumbled, staggering upstairs.

Mycroft locked the letters in his safe, then he sat in his armchair downstairs for half an hour, drinking a shot of whisky, because even though Sherlock was wrecked, he still knew exactly what he was going to find up there.

He eventually set his glass down, switched off the lights, and ascended to the upper level of the house, that unsettling sensation still fluttering in his belly. As expected, Sherlock had showered, towelled off, dropped all his clothes and the bathrobe on the floor of Mycroft's bedroom, and was now sprawled across Mycroft's bed. His damp hair was spreading a wet patch over one of the pillows, a set of pyjamas he'd pulled out of the wardrobe was untidily abandoned atop the duvet, and he was bare under the covers, asleep.

Mycroft stood beside the bed in the demi-darkness for long minutes, watching him by the light from the passageway beyond the room, until Sherlock stirred.

"Mmph… didn't mean to drift off… we haven't had our discussion yet."

Mycroft shook his head. "Not now. You're exhausted."

"Not so exhausted that I can't negotiate."

"Not with me, when you're not at your best. You know I'd take full, disgusting advantage of you."

"I was rather hoping you would."

"I'll leave you to your rest," Mycroft said abruptly. "You need it."

"Lie down with me."

"No."

"I won't touch you without your permission."

"I'm not certain that either of us has a particularly good grasp of what constitutes permission from the other."

"Lie here with me, anyway."

"Put on some clothes."

"Will it make any difference?"

"Perhaps you should tell me if it will."

Gazing up at him, Sherlock murmured: "We have enough to consider that one layer more or less of clothing barely constitutes a drop in the bucket."

Sherlock moved over to one side of the bed, and Mycroft exhaled in resignation. Shedding his dressing gown but keeping his pyjamas on, he got into bed, turning to face the one against whom he had no sense of self-preservation.

Never taking his eyes off him, Sherlock waited until Mycroft had settled under the duvet and was still. Then he quoted in a sleepy baritone murmur that sent shivers up and down Mycroft's spine:
"'Say that we had one father, say one womb
(Curse to my joys!) gave both us life and birth;
Are we not, therefore, each to other bound
So much the more by nature? by the links
Of blood, of reason? nay, if you will have it,
Even of religion, to be ever one,
One soul, one flesh, one love, one heart, one all?'"

"I see you've been raiding my library for more than just mythology," Mycroft remarked, suppressing another shiver.

"While you were gone, I looked at all your books again, and I remembered how often you used to read that play," Sherlock said. "It's a very well-thumbed copy you have there on your shelf. You've probably got the whole thing memorised."

"I took it seriously as a cautionary tale," Mycroft gave a thin smile.

"Gods take their siblings as their lovers and spouses."

"And the gods always punish mortals who do the same."

"Mycroft, you are a god in a world of goldfish," Sherlock chuckled sleepily.

"Your brain must have turned to pulp if that's the best argument you can offer me," Mycroft groaned.

"Not at all. We've always done what no one else could, Mycroft. So kiss me."

"Not a good idea."

"Because I mean the world to you?" Sherlock asked.

"You do remember."

Sherlock shifted a little closer to Mycroft. "If I'd kissed you then instead of just groping you, would it have made a difference?"

"No. Because you didn't want it, Sherlock. That was the heroin talking."

It was Sherlock's turn to shake his head. "No, I did want it. I just forgot. Like I forgot so many things."

"Now I think it's the fatigue talking. You're high on exhaustion, brother mine."

"I assure you that I'm in full control. I'm keeping my word, aren't I? I haven't touched you without your permission. But you can touch me. I'm asking. Kiss me, Mycroft."

"To what end?"

"I want to know. You want to know. Let's just find out."

"Is this how you blunder through your cases? Trial and error?"

Sherlock inched even closer. "Does it matter? In any case, I believe your conquering hero merits at least one kiss."

The unsettling sensation sharpened into a jolt, and Mycroft felt his face heating up again, only the darkness of the bedroom concealing his embarrassment.

"Don't do that," Sherlock whispered, his face just an inch from Mycroft's. "Not to yourself. Don't think all that… Not with me…"

Mycroft could feel Sherlock's breath on his lips, the heated air between them, the shifting of the sheets as Sherlock instinctively reached for him.

"Keep your hands to yourself," Mycroft reminded him.

"I just want…" he began, continuing to shift closer.

"I haven't given you permission to touch me – keep your hands to yourself," he repeated firmly, seizing Sherlock's wrists and pinning him back against the mattress.

It was an echo of the night his brother at 17 had offered to service him for drug money, somehow having just known that Mycroft desired him in ways he should never have. Now, rather than holding them apart from each other, Mycroft was holding him down, taking charge as he closed the virtually non-existent distance between them.

The unsettling feeling that had plagued him for hours dissipated as he reasserted control, no longer submitting to this unpredictable knight's recasting of Mycroft as the prize to be won. Perhaps they could play that game another day, but not now, not today.

"Mycroft…" Sherlock whispered against his mouth, lips brushing his, unclothed body pushing up against him as Mycroft pressed him down, his erection smearing pre-cum onto Mycroft's pyjamas.

It seemed that even when he was in control, he always gave in to Sherlock, so he pressed in closer and claimed Sherlock's mouth in a hard and demanding kiss, pushing his tongue in and tasting him hungrily, forcing a moan from his brother as he writhed beneath him. If Sherlock was repulsed, if this experiential step taught him that he didn't want this, if it was never to happen again – then this way he could pretend it was Mycroft who had forced it on him, and wipe it out of his mind if he wished…

But Sherlock was kissing him back eagerly, and the hardness he was pressing up against his thigh was growing. Mycroft released Sherlock's wrists and worked one hand into his curls, still damp from the shower, while his other cupped his brother's beautiful face. And he held his breath as he deepened his crushing kiss, waiting for the moment of truth, waiting to learn if Sherlock would push him away.

Sherlock growled.

Then Mycroft felt his brother's strong arms going around him in a command to stay where he was, one hand against the nape of his neck, the other on his back, pulling him closer, pulling him hard against him, drawing him in, wanting more, demanding greater access, communicating in a fiery wordless language that he had no intention of letting him go.

Note: The lines Sherlock quotes are from 'Tis Pity She's a Whore, by John Ford, a play that Mycroft has also quoted from in the preceding chapters.