John waved a final goodbye as a long black car containing two men and a small dog pulled away from the kerb in front of 221B Baker Street. He went upstairs to the rooms he shared with Sherlock Holmes and put on the kettle. Sherlock was already taking his ease, shoes off and feet up on the sofa as he thumbed through a tabloid.

"You told me you were taking on a little case," John said in a scolding tone. "Dog-napping."

"It was your idea," Sherlock said, in what was probably meant to be a placating manner. "You specifically instructed me to take on something that wouldn't make the papers." He rattled his newspaper pages loudly as John made an inarticulate noise of irritation.

The kettle burbled as steam poured from the spout. John didn't wait for it to shut itself off, he picked it up and poured into a plain brown pot, wincing as water splashed off the rim and scalded his fingers. "Ow! That was the Queen's corgi!"

"Precisely." Sherlock made it sound as if everything was blatantly obvious and John was just too obtuse to understand. "A breach of Royal security that serious won't be leaked. Unless, of course, there's another hole they haven't stoppered."

Whilst the tea was brewing, John poked around the cupboards for biscuits. Finding none, he poured tea and milk, carried the mugs into the living room and handed one off to Sherlock before settling into his own preferred chair. He took a sip and then conceded the point. "Yeah, I suppose you're right. Sherlock – " he began, hesitantly. "I wanted to say you were really good with that young page today. You could have been your typical dickish self, but you weren't. I was really proud of you."

"If the tool is defective, it's the manufacturer that should be cursed," Sherlock said as he stirred his tea. "Or in this case, the footman who put that boy in charge of the dog. Tommy was clearly good with animals, but a poor judge of people. Given those conditions, his actions were understandable. No one in the lower levels of the palace retinue, especially one so recently taken into service, would question orders from someone who appeared to be a senior official. Besides," he added, "the case wasn't without its points of interest. Frankly, John, I had fun."

"Fun?" John set aside his mug. "Exposing flaws in the security at Buckingham Palace was fun?"

Sherlock shot him The Look, the one that said, 'did you really just say that?' John had to concede again. "Oh all right. It was fun. Although I'm not sure showing off by using a penny and a spray bottle to shut down all the perimeter alarms was a good idea. I thought the Captain of the Guard was going to lock you in a cupboard and throw away the key."

"He could have tried," Sherlock said with blithe indifference to his potential loss of freedom.

"What about the rest of the ring?" John asked. "The ones who escaped."

Sherlock shrugged and drank more tea. "Well on their way to France, I should imagine, and into the arms of INTERPOL. Even if they get away, I doubt they'll trouble the corgis any time soon. Generally those types of contracts are one try only. It's as much about satisfying whims as anything, and whims are notoriously fleeting things."

"Tell that to the soldier who's just drawn dog walking detail," John muttered.

He watched Sherlock drink tea and frowned as his friend and partner's gaze turned inward. It was becoming a common event. Sherlock was worrying at a problem that he wouldn't discuss. If not distracted he would soon grow snappish and then be completely impossible to share space with. John drained his mug and then walked out of the room.

"What's this for?" Sherlock asked as John dangled his top coat in front of him.

"We're going out. Stretch our legs. What do you say we go over to Covent Garden Market?" Sherlock gave him a blank look of indifference to the idea. John pressed on. "All the old things to look at, they have stories to tell. The writing's going so well I'm thinking about branching out into original fiction. Maybe I'll find something there that will spark an idea or two."

"The blog entries are close enough to fiction as is," Sherlock replied disdainfully. He sighed. "All right." His expression seemed to suggest that he was only going out to humour John and would otherwise rather stay sprawled on the sofa until the black mood overtook him completely.

They didn't talk during the taxi ride. Sherlock retreated to his Mind Palace, and John was busy watching the city pass them by. He saw groups of tourists get on and off of a double decker bus, taking holiday snaps with cameras and mobile phones. They seemed to be having fun. It was a bit of a contrast to the locals who were rushing by, eyes fixed straight ahead, who looked like they were having no fun at all. It made him think and he was feeling a bit quiet himself as they pulled up in front of Covent Garden.

The historic market was busy. Shoppers and casual browsers meandered and haggled with row after row of vendors, each working off a table or a more permanent looking stall. Silver goods, china tea pots, memorabilia from half a dozen wars, and bric-a-brac of all descriptions spanned out before them. "Look at the history," John said as he bumped Sherlock's shoulder, calling his attention to a display of vintage medical instruments.

"It's not entirely dull," Sherlock conceded. He picked up a trocar and ran his fingertip along the barrel and the still razor sharp tip. "A device not dissimilar to this one was used in the 1875 murder of one Henry Wilkins, veterinarian. The murderer wanted it believed that the cow Henry was working on protested having its bloat relieved in such an abrupt fashion. You see, you take this device and one of these– " He picked up a cannula. "Puncture the rumen and release the trapped gas." He demonstrated poking a hole and then inserting the metal tube into the stomach of an imaginary cow.

John shook his head, bemused. Sherlock really did have an encyclopedic knowledge of murder. "So who did it?"

"A disgruntled suitor of Wilkins' daughter, a stable lad without prospects, named Alf Conner. He thought he could improve those prospects by getting Wilkins out of his way. The daughter, being the only heir, would have inherited a tidy sum."

"And what tripped Alf up?" John asked. His attention had drifted to beautiful locked tin box, about six inches deep and ornately enamelled in black and gold. He ran a hand contemplatively over its surface. It was the perfect size.

"Deep in his cups, he boasted of the deed. Not even the police of the day could bungle a case when a confession was made to one of their own."

John frowned. "That was rather stupid." He picked up the box to examine it more closely as Sherlock set down the trocar and cannula.

"Amateurs often are," Sherlock agreed. "But in this case, the constable wasn't known to Conner and he wasn't wearing a uniform."

John held the box out for his companion's inspection. "Sherlock? What do you think of this? It's nice, isn't it?"

Sherlock glanced over. "Dispatch box. Military style. The sort a soldier would have taken to India or other far flung corners of the realm." He turned the box over and looked at the description tag confirming his findings and then showed it to John. "Diamond Jubilee commemorative. What would you do with it?"

John shrugged. "I was thinking. There are cases of yours, like the one today. I can't blog about them. But I'd still like to keep a record. Maybe when you're retired and I'm old and need the income, I could write a book. The Secret Case Files of Sherlock Holmes." Sherlock glowered, but John pressed on. "Technology's always changing. I can store my work on memory sticks, but what happens in ten years time when we've moved on to wafers or something? I have to translate my files all over."

"So you're thinking … old school?" Sherlock suggested dryly. "Pen and paper? Should we look for a quill as well?" He opened the dispatch case, examining the contents. "It already comes with a pair of ink bottles."

"You're funny, Sherlock. A laugh riot." John felt his enthusiasm for the box and his project fade under Sherlock's mocking. He started to turn away.

"John!" Sherlock glared at the dispatch case and at John's slumped shoulders. He pulled out his wallet and rounded on the stall keeper who took the box and started to wrap it.

"Stop that man!" an outraged female voice cried out. "He's taken my bag!"

Heads pivoted, searching for the source of the scream. A youth, leather handbag in hand, turned the corner and ran straight at them. John reacted without thinking. He stuck out a foot and sent the bag snatcher tumbling. A few seconds later an out of breath and wheezing security guard ran up as a crowd began to gather.

Sherlock caught John's eye. He nodded back. The last thing either one of them wanted was more publicity. They started to stroll casually away against the tide of curiosity seekers and nearly made it. A dealer of vintage bonnets and other accessories said in a loud, clear voice, "I saw everything!" She grabbed Sherlock by the arm and propelled him forward. John had no choice to follow. "He stopped the thief!"

Sherlock's reaction would have been comical if it wasn't for the response of the crowd. "It's Hatman!" someone cried. Other voices joined in. "That's Sherlock Holmes! It's Boffin Holmes!" began to reverberate throughout the market, drawing more people. "Autograph? How 'bout it?" called a man's voice. "Pose for a picture, love?" said the Bonnet Lady. And then in a less happy tone, "Where's the hat? Why aren't you wearing the hat?" Someone tugged at Sherlock's coat hard enough to send him off balance. Someone else shoved John out of their way and he stumbled backwards. He lost sight of Sherlock as the crowd closed in.

John heard Sherlock's voice rising over the din as his attempts at politeness were ignored and he began to get well and truly angry. Worried Sherlock would resort to violence, he began to muscle his way back through the growing ring of onlookers, not bothering to apologise as he trod on toes and elbowed ribs. He didn't get far, someone gave him a hard shove in retaliation and he went tumbling sidewise, barely staying on his feet.

"Oi! What's all this?" a voice boomed.

"All right. Break it up. That's enough," said another, younger voice that was trying to be just as gruff and imposing.

The crowd began to shift uneasily. A few less dedicated gawpers moved away.

"On your bikes or I'll call for a van," said the first voice of authority.

From somewhere up the aisle someone blew several blasts on a vintage police whistle. Surprisingly, members of the throng, mostly older individuals and tourists, reacted and obediently cleared off.

"This way!" Someone laid a heavy hand on John's shoulder and tugged his arm hard. He glanced over. It was the vendor whose wares they'd been admiring when the trouble started. A few seconds later they were in the relative safety of an alleyway between the rows of market stalls. "That happen often?" the vendor asked.

John caught his breath. He could hear the sounds of more security officers arriving on scene and the crowd of autograph hunters being moved along. "Sometimes, yeah." He stuck out his hand. "Thanks. Sorry, I didn't catch your name."

"Bill." He clasped John's hand in return. "Bill Sanders. So that was Sherlock Holmes. You must be – "

"John Watson, yeah."

Bill pushed his eyeglasses further up his prominent beak of a nose. "He always get the credit like that?"

Before he could reply, Sherlock, looking rather worse for wear, the security guard and his prisoner, and a pair of constables appeared. "Excuse me." John said to Sanders as he watched Sherlock shake his head, disavowing any involvement in the entire affair.

"Are you all right?" Sherlock asked when they were finally close enough to speak.

The suspect, a weedy looking youth of no more than twenty, was cuffed, and one of the constables, a craggy faced man whose demeanour suggested he'd seen too much of life on the streets, recited his rights and then launched into a scolding for being such a pillock.

"Sarge," the second constable, a much younger and less senior looking specimen, cautioned. "You're not supposed to – "

"Yeah," John said, as they moved far enough away from the rest so they could hear one another without the others' talking over them. He took in Sherlock's dishevelled appearance and frowned. His colour was high and his hair mussed. Someone had torn buttons from his shirt, taking some of the cloth with them.

Sherlock followed his gaze and his face became a picture of dismay as he took stock. "My adoring public," he said as he fingered the ruined shirt.

"I did warn you," John said.

The sergeant glowered at the growing knot of people who surrounded him, and it seemed to John, at life in general. "All right. Get him out of here and get statements from that lot." He pointed at the victim and the bonnet seller, and then turned his attention to Sherlock. "Oh for the old days when you could cuff them 'round the ears and no one would say, 'Boo'. Now we have to worry about violating their 'human rights'. What about that lady's rights?" he asked, pointing at the victim. "What about yours? What about mine?" The constable shook his greying head. "The class of criminal today lowers the tone of policing." He sounded nostalgic for days gone by when criminals addressed the police as Mister.

"Looking forward to retirement, Sergeant Dunstable?" Sherlock said, dryly.

"Two weeks, Mr Holmes," the constable replied. "Two more bloody weeks." He sighed and seemed to visibly pull his thoughts away from a future that didn't include tone lowering young hoodlums. "So what's the real story, Mr Holmes?"

Sherlock shot him a glance and John shook his head, again signalling he didn't want to be involved. Sherlock shrugged. "I assure you, Sgt. Dunstable, I was otherwise engaged. I observed the disturbance, of course, but I didn't see what caused your suspect to fall."

Dunstable didn't seem entirely convinced, but he shrugged. "As you say, Mr Holmes. That's what will go in my report." He started to say something else, but his radio gave a short burst of static and a female voice read his call sign. "Excuse me." He turned away.

Sherlock seemed to think their business concluded and he signalled for John to follow him.

"Hang on a minute." John and Sherlock exchanged a glance and a shrug as Bill Sanders disappeared the way they came. A minute or so later he returned carrying the wrapped dispatch box. "You still interested?"

Sherlock pulled his wallet out. "It was two fifty, wasn't it?"

"Sherlock, no. It's nice, but I can't let you – " John protested.

"Twenty-five quid," Sanders said firmly. "And not a penny more."

John shook his head. "Not that we don't appreciate it, but I couldn't. That's much too generous."

"Listen, John," Sanders said. "Bags and wallets have been going missing for a fortnight, which just so happens to be the same amount of time that little toe rag has been hanging about. You did us a service. I'm just returning the favour."

John glanced up at Sherlock. He had a peculiar kind of smile curving his lips. When their eyes met Sherlock mouthed, "Be gracious", and John realised that the shoe was for once on the other foot. "Thank you," he said politely and he tucked the dispatch box under his arm before offering his hand to Sanders.

They shook. "You ever write that book of yours," Sanders said with a wink at Sherlock. "I want an autographed copy."

John glanced up at Sherlock and saw the subtle signs of renewed irritation at the mention of a book. "It may be a while."

"A long while," Sherlock grumbled as he buttoned his coat over his ruined shirt. "Come on, John. I think I've had enough fresh air for one day."

John nodded as he watched Sherlock shake hands with Bill Sanders. A sense of foreboding eroded the warm moment. Sherlock had been mobbed before, but it was usually coming to or going from Scotland Yard, or occasionally on their own doorstep, and that was by the press. The public, up to that point, had been generally respectful, and the encounters with deerstalker bedecked girls a bit of fun. It looked like all of that was about to change, and he wondered if he and Sherlock were up for the challenge.