A.N. So so so excited for this challenge to start! First prompt from my dear silvermouse – Museum. FYI, the Black Museum and the Lambeth Poisoner are true.

It was a short while after his prodigious return to life that inspector Hopkins invited Holmes to Scotland Yard. Naturally, the sleuth promptly agreed, thinking his young admirer might have a case for him – and just as naturally, Watson followed him.

It was with no little surprise that they were instead led to the Black Museum – the museum of criminal relics of Scotland Yard, that many an important figure had deigned to visit, as the visitors' register attested, despite its peculiar subject.

Holmes, though, scoffed at the idea of signing the register. "There is no need to let traces of my presence, Hopkins – do you really want to be known that you bring people around to brag when there's no need to allow access? It is still not a place for anyone,"

"Well, you're not anyone – this is a place intended for investigators' instruction, so I suppose you have every right to be here," the young man said cheekily.

Holmes glared. "I'm sure policemen need all the instruction they can get," he replied. "Is there a point to our being here?"

"Oh please Mr. Holmes. I'm sure you'll like it," Hopkins insisted.

"It might be amusing," Watson agreed – and the detective caved in.

The young inspector had been right in his hope that his idol would be interested in the exhibit, if unimpressed. But from someone who might have opened a whole new wing if he'd donated the memorabilia of past cases that haunted 221B Baker Street it was perhaps to be expected. Holmes, though, was informed about almost all the cases on display and was caught smiling at some of the things exhibited and somehow asking about a detail. Watson, instead, was much more vocally appreciative, while his questions were less work-oriented, and Hopkins smiled. The doctor's presence was always a pleasure.

"I wouldn't think that you'd want to commemorate your failures," Holmes pointed out in the room dedicated to Jack the Ripper.

"It might very well be the most famous case of the century - it's practically the reason we get noble visitors at all, everyone is so curious about it," the young inspector admitted, with a shrug. The killings had stopped at least, though no one had ever figured out why. Hopkins would be ready to suspect his guests' involvement, but asking outright would bring him nothing – Watson would disclose when he was at liberty to do so, if they were really involved.

Fine, maybe he wasn't entirely honest in his words – maybe the Ripper would be the second most famous case of the century. But to exhibit the evidence of having rounded up the criminal mastermind Moriarty's British gang while letting the chief and the most dangerous members escape would have been more shameful than showing a proper unsolved mystery. Hence why nothing from that case made it into the museum.

"And this is to show we've not been entirely idle and helpless in your absence, Sir. The evidence from the Lambeth Poisoner, Thomas Neill Cream. Our cousins the Americans had jailed him, but then they let him go – and he moved here to continue his murderous career. Until we stopped him in 1892," Hopkins announced proudly.

"I remember that case," Watson said, smiling fondly.

"Oh yes, doctor – you helped tremendously. Were you properly thanked?" the young inspector replied, with the same puppyish admiration in his eyes he used to reserve to Holmes alone.

"Oh, no need to," the doctor answered, embarrassed by the question.

"You continued to work cases after we…parted?" Holmes asked, surprised, hesitating a bit on the less grating wording for what had happened at the Falls and ultimately settling on that. "I thought you'd be much too busy with your flourishing practice."

"Oh, just a few post-mortems here and there, amiable chats with a few Yarders…" his friend remarked, understating his contribute as always. He wouldn't say how much it had meant for his sanity at the time to still be somehow involved in detective work, or how guilty he'd felt once Mary had fallen ill, doubting he might have missed the earliest symptoms because his mind was on murderers or killing methods…

"The inspector who solved that case told me your help was capital, doctor," Hopkins praised warmly.

"The poisoner was a doctor – I suppose that's why my input was useful at all," Watson said, shrugging.

"Nonsense," Holmes interjected. "Do not put yourself down, my dear. I can attest myself what a great help you are to solving cases myself. It is no wonder that the inspector would find you a just as useful conductor of light."

Watson blushed lightly at the praise.

"Thank you for organising this visit, Hopkins. It was not what I expected, but it was pleasurable – and indeed, in some respects instructive," the sleuth added.

The young man beamed. "I did hope that you'd like it, Mr. Holmes."