"Gone?" I stared at Lestrade, mouth open. "What do you mean, the prisoner's gone? That poor man wasn't nearly fit enough to be taken anywhere!"

"I'm sorry, Doctor." Lestrade took a file from the top of a teetering stack and passed it over. "I would've sent word earlier this morning, if I'd thought it would do any good. The press are already calling his lodgings 'The Lambeth Bomb Factory', and my... our superiors take an understandably dim view of potential terrorists – even accidental ones," he added wryly. "Given the circumstances, the superintendent decided he should be moved to a more suitable facility before the trial."

"What kind of facility?" My eyes narrowed; strangely, no specific institution had been named in the paperwork, but my colleague's expression was eloquent. "Lestrade? It wasn't Bethlem, by any chance?"

"Just until someone can determine whether he'll be fit to plead," Lestrade hastened to reassure me, but I was barely listening. Bethlem Hospital! Known deservedly by all and sundry as Bedlam... And I... dear God, had my deception in that report over what the prisoner was really researching led the superintendent to believe my friend might be criminally insane? An old experiment of Holmes's, terminated by me due to its potential explosive qualities, had seemed such a plausible alternative... Rash, deluded idiot that I was, in shirking my sworn duty, I could so easily have sealed the poor man's fate!

"Watson?" I flinched at the hand on my shoulder, insides writhing at Lestrade's tone of concern. My colleague was no fool, had he already realised what I had done?

"Don't feel too badly about it, now, Doctor, we've all been there. I'm sorry, I should have seen this coming..."

"...What?"

"Happens to the best of us," Lestrade went on, giving my shoulder a kindly shake before releasing me. "Lord, the yarns I've had spun at me over the years would've done an Irishman proud! I know you've been... well, in the habit of exercising your own judgement over a suspect's innocence, you and Holmes... but that isn't your job here, Doctor, or mine. In cases like this, our duty is just to ensure that the right people and evidence get to court in one piece, nothing more."

I nodded glumly, relief and shame warring within my breast. This was but a brief respite before Lestrade – before everyone! – learned of my deceitful conduct. If I wished to retain a shred of personal or professional integrity, I would have to confess all, tell Lestrade what the exploded tube had truly contained... My God, the tube!

"Er... Lestrade, did you visit the fire station this morning? You know, to see if the fire crew salvaged anything from the man's lodgings..."

"Oh! Sorry, Doctor, it went right out of my head. Yes, I did drop in there, and no, they didn't find anything like what you described. I guess that explosion must have reduced it to scrap!"

"Yes..." Or someone else had gained entrance in all the confusion... but who? Useless even to speculate just now, the possibilities were endless. The whole of Marylebone had known about Holmes's experiments, so it was nonsensical to think that 'The Lambeth Bomb Factory' had gone entirely unnoticed by my new friend's neighbours before the explosion, no matter how discreet he'd thought himself! And I still didn't even know his name...

~0~

"Inspector." The constable on duty touched his helmet, stepping aside. "Mind how you go, sirs – s'not much left holding the place up, I shouldn't wonder!"

"We'll be careful, Biggs," Lestrade nodded. "A quick look round is all we want. Watch your step there, Doctor."

Lestrade had raised an intrigued eyebrow when I stammeringly asked him to accompany me to the site of the explosion, but mercifully refrained from asking awkward questions on the way. This may have been partly due to Mary's tight-lipped reaction to my sending her home in a different cab from the Yard, my promise to explain everything when I returned home notwithstanding. It couldn't be helped, however. My wife could hardly accompany us to the scene of an ongoing police investigation, and I was reluctant to confess anything to Lestrade without making some attempt to corroborate my tale with hard evidence, whether that was the remains of the tube or its contents, or some clue as to who might have taken it.

And indeed, our 'quick look' did turn up something of interest. A charred timber had fallen across what could only be the remains of my friend's apparatus, and one of the nails jutting from the wood appeared to have snagged someone's outer garment: a few strands of fine, grey wool clung to the blackened metal, apparently untouched by flame or smoke.

Lestrade fished a small paper bag and a pair of tweezers out of his pocket, and carefully unhooked the strands. "Hm, looks like somebody was here after the fire crew... and well dressed, too, this is top quality cloth!" My colleague frowned, putting the evidence delicately away before turning back to me, voice strangely nonchalant. "Funny, isn't it, the way history always seems to repeat itself."

A tingle of unease crawled down my spine. "Does it?"

"Oh, aye... like that experiment our prisoner claimed he was conducting in your report from last night. Now, maybe my memory's faulty, but I seem to recall you telling me once about Holmes trying to carry out that exact same experiment at Baker Street..."

I felt suddenly cold. Damn and blast, I had completely forgotten that I'd gone for a nerve-steadying pint with Lestrade that very afternoon!

"Watson..." Redfaced, I steeled myself to meet my colleague's eyes – and thank God, Lestrade's expression was one of almost fatherly concern. "Why are we really here?"

I could only stare. "You... knew? But..." Why had he waited so long to mention it, and to me of all people?

"You wouldn't keep anyone's scientific work secret without a damn good reason, Doctor. This case is a lot bigger than some lab accident, isn't it?"

~0~

I spent most of the cab ride back to the Yard telling Lestrade everything I knew, whereupon my colleague spent the remainder of the journey trying to persuade me not to turn myself in. "I don't like this, Watson, not at all. Look, I can't say any better than you whether our man was right about how close he was getting... but you can't have been the only one who knew what he was trying to do. Why else would our superiors hustle him out of the public's view so fast?"

"But what does that have to with my conduct?" I argued. "I'm fully prepared to accept whatever decision..."

"Give me strength!" Lestrade groaned. "Think, Watson: how's it going to help anything to admit to our superiors, in a private hearing, that you kept quiet about something that's already lost one man his right to a public trial?"

"Oh, come now..."

Lestrade snorted. "I can just see the headlines in the paper: 'Diamonds common as coal!' You know as well as I do, there's no chance now he'll ever be deemed fit to plead! And I wouldn't rate your chances any better, coming forward." He smiled grimly at my astonished expression. "I'm not about to lose one of the best damn officers I've ever had, just for being wiser than he knew. You'll oblige me, Doctor, by staying right where you are, and keeping your eyes and ears open, same as me."

I nodded slowly. "Well... if it's eyes and ears we need..."

~0~

"A most interesting story, gentlemen." Mycroft leaned back in his chair, fingers steepled, and gazed at me keenly. "Curious that, out of everyone in whom he might have confided, our man chose you, Doctor. Tell me... in your professional opinion, given enough time and resources, could he have achieved his aim? Created a diamond of sufficient quality to at least deceive the average civilian?"

"Er..." There it was, the inevitable question that I had been dreading having to answer. "I... believe so..." But in truth, that fire-eaten look in my friend's eyes had been all the data I really needed. "Yes, I rather think he could have."

"Thank you, Doctor." Mycroft gave me a grave little smile. "It is a great shame that none of us can do any more now than guess the fate of the experiment's remains, but there it is."

"But what of the prisoner himself? You seem certain that he is at Bethlem, do you not think..."

"I think he will do well enough there for the moment, Doctor." Mycroft's voice was kind enough, but with an undernote of iron. "No doubt visitations could easily be arranged for his closest family – provided, of course, that they did not hamper the poor man's recovery in any way."

I had only kept my mouth from falling open with the greatest difficulty. Of all the naïve idiots... I had so long thought of Holmes's older brother as another friend and colleague, I had entirely forgotten Holmes's half-casual warning from years earlier: "Mycroft is the British government." What in the world had made me think that Mycroft would not share Whitehall's views about man-made diamonds, or fail to ensure that 'our man' could cause no economic mischief with them? The only error on Whitehall's part appeared to have been losing track of the tube and its theoretical contents... And of course, any of those second-rate diamonds would be a mere booby prize, compared to the minute traces of flux that might still be clinging to the inside of the tube! Without that, anyone else attempting to recreate the flux's composition on their own, with a view to improving the formula, would have an insurmountable task.

As I sat with mind awhirl, I was vaguely aware of Lestrade making the appropriate concerned noises. "...but we mustn't keep you from your work any longer, Mr. Holmes. It was very good of you to take the time to see us. Come along, Doctor."

I managed to mumble something suitable in Mycroft's direction as we left, and then, thank God, we were finally back out in the street. I took a few deep breaths, uncaring of Lestrade's scrutiny, eyes stinging at the sudden overwhelming desire to purge my lungs of anything that remained from that den of... of bureaucracy. Heaven knew, Holmes had been perfectly capable of acting like an automaton towards myself or a client when he wished, and those incidents had all been repellent enough; but to see that same heart of marble in the elder Holmes, and over such a delicate affair... In my current frame of mind, I could almost hope that this friendship had also just come to an end.