Chapter 12

John was getting used to the rigmarole of setting off metal detectors. Every time he went abroad he had to explain about the pins in his shoulder. He wished he was somewhere exotic now, anywhere but the fortress that was Thames House, while the MI5 security personnel swept him with a hand-held and patted him down. Sherlock suppressed a smirk as he deposited his iphone and the broken phone in a grey plastic tray. The officer assigned to escort them, a hulking great lad in his early twenties who John thought would be better placed in a career in professional rugby - Jesus, was everyone taller and better looking than him? - had given Sherlock a funny look when he'd produced the homemade alpha detector from his pocket.

"New Zealand," said John.

"Hmmm?" Sherlock took possession of his greatcoat from the officer.

"I'd rather be in New Zealand."

"Oh, right." Sherlock's expression clouded as they followed the MI5 officer up the steps to a mezzanine floor of the lobby.

Sherlock had of course been here before and knew the drill.

"What's he doing here?" Mycroft met them at the lifts, one eyebrow as arched as the crook of his umbrella.

"Nice to see you, too," John bristled.

"He's my medical," Sherlock entered the lift first, snapping his heels as he turned to face the doors, searching for the appropriate word, "maven."

"Should have know you'd never travel without one. How is married life treating you, John?"

"Wonderful. You should try it some time."

"If you do, be sure to give me plenty of notice, Mycroft," Sherlock teased, "I may well be attending the freezing over of hell."

The unnecessarily young and bulky MI5 officer key-carded the security panel and pressed the button for the fifth floor.

Sherlock and Mycroft maintained an uncomfortable silence until they were uncomfortably seated at a boardroom table facing representatives from the Security Service, MI6, GCHQ, the Health Protection Agency and Counter Terrorism Command. Mycroft, however, did not take a seat at the table, preferring to lurk near a huge TV screen at one end of the room, and John took that to mean he was here as more of a facilitator than a participant.

"Any chance of coffee?" Sherlock made a discrete aside to the escorting officer as they arranged themselves, "thanks."

"Deputy Director Wellington Cobham," a middle aged man stood and introduced himself, more for Sherlock and John's benefit than anyone else's. "Our coverage throughout the day indicates there is a credible and serious threat to the city."

"What have you got so far?" said a thin, pallid man named Nathan Dywer, deputy director of MI6.

"HPA has identified five potential weak links," said Professor Jackie Lavender, chief executive of the Health Protection Agency, "St Bart's has been locked down and crisis centres are being set up at St Thomas's as we speak. Fifty two cases of suspected contamination have been identified. There are two deaths we think may be contributable to the alpha radiation. We won't know for sure for at least twenty four hours because the diagnostic process is so long. I've got my best people working on it now. Public information needs are moderate to severe. If you'd like to take a look at the abstract…"

Lavender handed out document folders with the HPA insignia on them. John skimmed over a lot of the jargon, but one thing was certain; Sherlock had been absolutely right about the Polonium. "Am I, Uh, security cleared for this?"

"Don't worry, Doctor," Mycroft assured him, "you're not going to hear anything in here that you wouldn't already know, living with my brother. Besides, you were cleared for zero-zero-one graded material since the moment you entered Buckingham Palace."

"Oh, right," said John, "Uh, thank you, I suppose?"

DCI Chris McCullough of the CTC was the next to address the group, using a tablet to control the screen at the other end of the room. "At the moment our chief suspect is this guy, identity unknown, a confidence trickster and a known associate of several organised crime rings, although we've never been able to pin anything concrete on him."

Dywer scratched the bridge of his nose. "He's also been active internationally for the last two years."

McCullough played the CCTV footage from Bart's museum, sweat and fatigue glistening on his dark brow. "Latest known alias; Robert P. Wade, a master of disguise - "

John heard Sherlock cough 'bollocks' into his fist, as the coffee arrived on a tray.

"And we think he may have contacts in the Russian Federation. That's where I defer to you, Director Dywer."

"Yes, thank you Inspector," Dywer poured himself coffee and pulled his paperwork toward him, "our CHIS has brought up nothing so far, but we're trying to find links with either Al Ghurabaa, or the Lybians operating in Russia."

"What a load of old twaddle." Sherlock muttered under his breath.

"CHIS?" John whispered.

"Covert intelligence." Sherlock started spooning sugar into his coffee, keeping his eyes on Dywer. He got up to four heaped spoonfuls before John struck out a hand to stop him, moving the sugar bowl further away.

Lavender continued, sipping her beverage gratefully. John guessed she was stressed and tired. They all had a long night before them. "We believe the radioactive material originated in Russia. Our radiation expert is en route from a conference in the states, so in his absence, Mr Holmes will have to do. It was after all, he who alerted us to the threat."

"Please," the elder Holmes stepped forward, chin tilted in acknowledgement of his brother, "go ahead. Don't let us steal all your thunder."

"Polonium," Sherlock began, glaring at McCullough, "sorry I didn't have time to prepare a power point presentation. I didn't know I'd be giving a crash course in alpha radiation. I'll spare you all the irrelevant data. Specifically we're dealing with an isotope; Polonium 210. Half-life of one hundred and thirty eight point three seven six days. Two hundred and fifty thousand times more potent than hydrogen cyanide. One micro-gram is enough to kill a man. Although the radiation from Polonium doesn't reach very far, two to three centimetres at best, it can be described as very potent, ferocious even. If ingested it causes irreparable damage to the internal organs and the bone-marrow in particular.

"Ladies and gentlemen, this is the mother of all radioactive contaminants and I believe our terrorist is planning some kind of dispersal over the city, some kind of… dirty bomb. After a hundred and thirty eight days the risk is significantly reduced, so one would theorise that whatever organisation this is, they would be able to simply march in and take over the capital. But that short half-life does mean that whatever they're planning, it has to be soon, otherwise the material they spent so much effort getting into the country would be rendered useless."

"Are we talking large numbers of instantaneous deaths here, or is it a slow burn scenario?" Cobham sipped his coffee through his moustache, involuntarily considering the consequences of the drink perhaps being contaminated. Radiation affected everyone that way. Even if they weren't directly affected, it made them paranoid because they didn't fully understand it.

"That would depend entirely upon the amount and method of delivery. It's not like a regular radiological weapon, but if ingested, death is pretty much guaranteed within days, maybe even hours. Death by Polonium was unheard of until today, seeing as it's only ever used in industrial applications and then only in tiny doses. Somehow our terrorist has obtained unprecedented amounts and secreted away it inside the Romanian girl for transport.

"Actually, I seem to remember there were some studies done on animals as a sort of hold-over from the Manhattan project. It might be worthwhile to track that down."

Lavender made a note of this. "We spend most of our lives training for the unexpected, but no-one has ever thought to plan for this."

"No one's ever thought of doing this before," Dywer added.

"Not with Polonium, no," was Cobham's contribution.

"Actually, someone has thought of it before, haven't they dear brother?" Mycroft approached the table, a smug smile on his face.

"It was completely hypothetical - " Sherlock seemed to realise what his brother was doing because all his confidence seemed to evaporate and he looked rather intently at his cup of coffee.

"Sorry, who thought of it before?" John leaned forward to try and get a good look at his face.

"It was a mathematical model of the epidemiology. It's not like I used actual Polonium, that would be completely unethical - "

"It would take a genius to come up with a plan like that," said Mycroft, "but it wouldn't take a genius to get hold of it,"

"Get hold of what, Sherlock?" asked John.

"His master's thesis on the methods and effects of alpha particle dispersal on environmental organic chemistry," Mycroft announced triumphantly.

"So that's how you know so much about Polonium." John started to get cross.

"He was going through his Marie Curie phase." Mycroft was almost apologetic.

"I'm going to need a, uh, copy of that," said Lavender, the shock of this revelation apparent on her face.

"Sherlock, you tit," John said through gritted teeth.

"That's rather specific to be a coincidence." McCulough's expression was way too accusing for John's taste.

"That's because it's not a coincidence," Sherlock admitted, "I have reason to believe someone's stalking me."

"Who's stalking you?" John needed to know. If someone was following Sherlock, threatening him, then it concerned him as well.

"The flowers, John. The poppies. It's all part of a conspiracy to discredit me."

"But poppies? I don't - " John frowned.

"One of my targets, as you already know, on my hunt for James Moriarty's crime syndicate was a former Albanian warlord by the name of Baron Eduart Maupertuis. I traced a man thought to be Maupertuis' illegitimate son to a military installation in Serbia. This man was believed to have been responsible for a number of death squads back in the conflicts of ninety-two. However, my sources claimed he escaped justice and was still at large, making a name for himself in his father's business. The opium business. Hence the poppies."

"You have a name?" asked Dywer.

"Unfortunately I was disturbed during my investigations at the base, and I - I didn't have the chance to get a name, o - o - or a face."

"So what you're saying is, this Maupertuis character had a son and the son is exacting his revenge by sending you flowers - " Cobham was incredulous.

"And besmirching my name by carrying out a terrorist attack on London using a scientific paper I wrote."

"You realise how this sounds - " McCulough scoffed.

"If Maupertuis did have a son, then we'd have intelligence - " Cobham was beginning to resent this attack on his people's proficiency.

"Your intelligence was wrong! And it nearly cost me my life. What the hell did you think I was doing in that place?" Sherlock's eyes pleaded with his brother for validation.

"The burden of proof was on you, Sherlock. I think you had a lapse of judgement and you went off piste. The only thing that saved you from your overestimation of your own abilities was me wading in to save you, as always." Mycroft was not forthcoming in Sherlock's defence. In fact, it seemed to John that they were ganging up on him and had only brought him here to humiliate him.

Sherlock rose to his feet and pushed the chair back into the table rashly. John noticed that the officer who had escorted them tensed slightly in preparation for a confrontation. He prayed that the Holmes brothers weren't about to engage in a domestic in front of the five most important people in the security services. "I'm telling you, Maupertuis had a son and he's still out there, this is not Al Ghurabaa, or bloody Al Qaeda, it's Maupertuis Junior - "

"You assured me you'd neutralised the Maupertuis threat - " It was just Sherlock and Mycroft in the conversation now, facing off against one another, the rest of the table watching with concern on their faces.

"You put those words in my mouth. I said the Serbian side was the last piece of the puzzle, you inferred what you wanted from that - " Sherlock was getting agitated now, gesticulating wildly and raising his voice.

"Do you mean to tell me, that you left things out of your report? This is serious Sherlock - "

"How did I know you could be trusted with this?"

"Oh, for heaven's sake." Mycroft did an epic eye-roll.

"Mycroft, you assured me that you could keep him on a short leash." Dywer turned on him.

Mycroft ignored Dywer and continued berating his little brother. "Oh, it's all coming out now. In any event, I'm ordering you to stand down. You are no longer an asset to the agency and you will cease and desist from this case."

"You're freezing me out? You can't do that."

"Oh, I assure you I can and will. All this claiming someone has a secret vendetta against you is just to cover up your own guilt over the Polonium. You did this, Sherlock."

"One of my friend's lives is at stake."

"Collateral damage at this point, I'm afraid, Mr Holmes," said Cobham, "thank you for the brief. Mumford will escort you out."

"You haven't heard the last of this, Mycroft."

"Brother dear, if you persist in your investigations I will have no choice but to assume that you are complicit in this terrorist plot and I will have you arrested and detained indefinitely at one of our black sites. Is that clear?"

Sherlock pouted aggressively.

"I said, 'is that clear?'."

"Perfectly clear."

John got up and silently ushered Sherlock out of the conference room.

Red, yellow, orange and white lights all blurred together in the dark city.

"What the hell was all that about?" John looked out the tinted window of the black government car as they were driven back to NW1.

"If Mycroft sees fit to humiliate me in front of the very people who require my help I cannot be held responsible for the consequences."

"Not that. I mean your thesis."

"Oh, that," Sherlock dismissed the idea with a hand, "It was one of three proposals I made. The other two were - "

"No," John's voice had a note of warning in it, "I mean, it's possible, probable even, that this whole terrorist thing is your fault."

Sherlock seemed to consider that for a split second. "I can hardly be held accountable for something I did when I was twenty-two."

"Hardly - You weaponised Polonium, Sherlock. Couldn't you just stick to the classics?"

"It was more fun."

"Fun," John pinched the bridge of his nose.

"What do you want me to say?"

"I don't know. Maybe I want you to stop being such an arse-hole and acknowledge that one of your best friends – don't make that face, yes I said best – might die because one of your arch enemies – let me finish – looked up your research and decided to put it into practice, which you have to admit, is pretty fucked up. Not to mention the risk to the rest of the country - "

Sherlock cut him off. "She's not going to die."

"What?"

"She's not going to die. She wouldn't be worth anything to them… damaged."

"What about the Polonium?"

"She's not contaminated either."

"How do you know?"

"Seriously, John, are you permanently confused. Do keep up. Because she used my phone after handling the body and my phone isn't contaminated. Neither am I, thankfully."

"Okay, right. Do you think they know she's not contaminated?"

"I'm counting on it."

All the time they'd been talking, Sherlock had been fiddling with the lock on the door, obviously a trick he'd picked up as part of his tradecraft, although John couldn't see exactly what he'd done. With one quick glance toward the driver, Sherlock flung the door open and leapt out into the traffic-jam.

"Shit!" John barely had time to scoot over and follow before he lost sight of the maniac. The door slammed shut behind him and he didn't have an opportunity to see if the driver had responded to what they'd done. He wound his way through the slow moving traffic toward the imposing arches of Hyde Park Corner, narrowly missing being run over by an impatient BMW.

"Did you see that? The stuttering, the micro-expressions. The stress is starting to get to him."

"Hmmm, yes. I fear your brother's usefulness to this organisation may be coming to an end." Dywer gazed out of the fortified window of the fifth floor conference room, roughly in the direction that Sherlock Holmes and Doctor Watson had been driven, although they were long gone.

Mycroft lurked at his elbow. "In a perverse way, I hope his usefulness has come to an end."

"He seemed a bit, well, pissed that you brought him here just to pick his brain and then bulldoze over his credibility."

"I'm reluctant to send him back into the fray. If it means, as you say, 'pissing' him off for the time being, then so be it. He's his own worst enemy and I'd do anything within my power to protect him, Nathan, you know that."

"Does he know that?"

"It's irrelevant how much Sherlock knows about what I do for him. But it is best for everyone if he doesn't investigate his own stalker, wouldn't you agree?"

"He's no intention of standing down."

"Indeed. But let's not fail to take advantage of that fact."

"You believe everything he said?"

"Of course." Mycroft sensed Mumford coming into the room behind him. "Where is he now?" he said without turning.

"Just entering Hyde Park, sir." Mumford consulted the tablet in his hands.

"Better stay hot on his heels if we're to find this Maupertuis."