Disclaimer: What wasn't thought up by Arthur Conan Doyle comes from the imagination of Steven Moffat and Mark Gatiss and belongs to the BBC. No harm or material profit is intended.
Credit: Huge thanks to crocodile_eat_u for their quick beta. Anything weird still in there is my own damn fault.
Feedback: Yes, please. Comments are more than welcome.

-X-

"DI Lestrade?"

"Yes?" Lestrade looked up from his papers to see one of the lab techs that regularly worked with Anderson.

She held up a folder and then placed it on his desk. "Ballistics from the shooting in the planetarium."

"Oh, yes. Thank you." He nodded at the tech and she was gone again, business done. He picked up the folder, intending to file it away until he had the time to devote to that particular case, but it fell open and the report slid out. The report's summary caught his eye as he straightened out the pages. 9mm rounds, matching the shell casings found. The casings were the same as the ones the British army used for their pistols, with ejection markings on the casing matching those of a Browning pistol, standard issue officer's sidearm. The striations on one of the bullets… looked familiar.

Lestrade put down the folder and started to dig around in his file cabinet. Right now, the write-up of the explosion at the pool could wait. It never did feel right to do the paperwork on a case he hadn't entirely closed yet. He found the file on the taxi driver murders (it bore the label 'A Study in Pink' – Lestrade still hadn't found out who'd had the morbid sense of humour to take Watson's blog title and put it on the case file). The ballistics report on the bullet taken out of the murderer's corpse was all the way at the back; the very final thing added because it had been a dead end. It had also been a 9mm bullet and it had remained intact enough to preserve some firing markings, which were pretty much identical to the ones from the planetarium.

And Sherlock had been at the planetarium, just as he'd been at the college where the taxi driver got shot. Not just Sherlock, either.

"You're looking for a man with a history of military service, nerves of steel…" Sherlock had said, and looked over to John Watson who was standing on the other side of the police line. Then he'd denied his own words and walked off. Which was so unlike Holmes it really should have made Lestrade wonder. But he'd been busy enough already at the time.

John Watson. Doctor John Watson. Captain John Watson, MD, in fact, as Lestrade had only found out when Donovan had almost gleefully dropped a court order with Watson's record on his desk. God knew where she'd got that one, but it only took half a word to the judge to get the ASBO dismissed, so he supposed he should be thankful.

Not for this, however. Damn it, civilians – even formerly military civilians – weren't supposed to have handguns. Especially not high-functioning sociopaths or PTSD-sufferers, no matter how well they covered for their afflictions.

The taxi driver case had ended reasonably well and no one had actually been shot at the planetarium. Lestrade also hadn't physically caught Watson with a gun, which meant he didn't have to make a case of it yet. But he'd have to have a word with Watson at least, because some things were just a bit too far outside the law even for a desperate man. This wasn't just bending rules until they might as well be in knots, this was outright breaking them.

-X-

221b Baker Street was neater than Lestrade had ever seen it. The carpet and wall hangings were still as outdated as ever, but someone had stowed away all the miscellaneous junk that usually lay around the flat.

He was studying the one modernization he had not noticed before – a series of holes in the wall that perfectly traced the yellow outline of a smiley face. Bullet holes. The last time he'd been in the flat, this wall had been covered in Sherlock's case notes. Well, at least Sherlock had shown some discretion, then.

"Sorry to keep you waiting," Watson said, while he laboriously climbed the final steps of the stairs. He was using a cane again and it clearly hurt him to walk. But he'd refused help and in fact had invited Lestrade to go on up while he made his own way. "Mind if I sit?"

"No, not at all." Lestrade made his own way to the chair further from the door and sat down as well.

Watson lowered himself into the chair with just a slight groan of relief. He then focused his attention back on Lestrade. "What can I help you with, Inspector? Any news of Sherlock?"

Sherlock was gone. Watson claimed he had also been in the building when the explosion went off, but the only one the firemen had been able to drag out of the rubble had been John Watson himself, badly injured and soaking wet. It had taken three days before he'd been coherent enough for a deposition and only then did it occur to Lestrade (who, let's be honest, had plenty of distractions during the whole mess) that where Watson was, Holmes shouldn't be this far behind.

The last thing Watson said he remembered of Sherlock had been his friend dragging him into the pool as soon as the both of them realized the bomb would go off. After that, nothing. Two uniformed officers had found Holmes's coat and jacket, both discarded into semi-public waste containers, but no other sign of him.

Lestrade shook his head. "No news, I'm afraid."

Watson frowned. "This isn't a social visit, though, is it?" He was tapping the armrest of the chair with his left hand. Watson noticed Lestrade's looking at his hand, and he grabbed the armrest to stop.

"It isn't, no." Lestrade took out the folders with the ballistics reports and dropped them onto the table. He shot another look at the smiley face on the wall, too. "We got the ballistics report back from the planetarium. Where you had that struggle with the … Golem, was it?" At Watson's nod, he continued. " It would seem the bullets we found match the gun that was also used to shoot the cabbie."

"Oh, really?" Watson was doing a credible job of sounding politely interested. After a few seconds, he went on, "well, we already knew the cases were connected, what with the phone and all."

"Hmm." Lestrade looked him in the eye. "Have you ever fired a weapon in anger, Doctor Watson?"

Watson smiled at Lestrade; the smile slightly forced. Then he looked away. "I was a soldier, Inspector. I've defended myself."

"What about after you came home?"

Watson remained silent. Lestrade looked at the wall again, then nodded to indicate the smiley face. "If I were to dig one of those out, what would I find?"

Watson shrugged. "I have no idea." He was sitting back now, both hands in his lap, completely relaxed. On the outside, at least. "What are you implying, Inspector?"

Lestrade was absolutely certain, now. He'd never be able to prove it with the evidence he had, but his gut told him those bullets had come from Watson's gun. That meant the man had coolly shot at least one person (criminal, but that was neither here nor there) and then successfully concealed it. Under the noses of Scotland Yard. Now he was sitting across from Lestrade, just as calmly as that night. Still recovering from severe injuries. Utterly non-threatening. Lestrade suddenly wanted to be on his feet for some reason.

He got out of the chair and made a circuit of the room. He couldn't back out now. Now he had to either make his accusation, or decide to hold his tongue. If he did, then he'd be holding it forever, until it became his downfall.

Five years ago, he'd decided that Sherlock Holmes' brilliance justified bending a few rules. It had paid off, and paid off well, but it was always hard going. Three months ago, this Watson character had stepped onto the scene and immediately clicked with Sherlock as if he'd never done anything else. Sherlock became much easier to get along with, and Lestrade's solve rate had fairly shot up. Not just Lestrade's, either, if the reluctant gratitude DI Dimmock had expressed while cursing Sherlock's name was anything to go by.

John Watson had kept Sherlock Holmes focused, and just occasionally reminded him that there were people behind all the interesting cases. And also, apparently, kept him safe. That was some friendship for people who hadn't even known each other for that long.

In the end, that did it. Lestrade couldn't make himself level accusations – accusations he couldn't even reliably back up, at that, at the man who, somewhere under that eerily calm exterior, was even more worried than Lestrade about his missing friend. Most likely feeling guilty, too, because he had killed to protect the man once already and now he'd failed.

"I'm not implying anything," he said after that long silence. He went to take the reports off the table and present them to Watson himself. He stood over the man until he looked up. Then Lestrade moved his head to indicate the bullet holes in the wall. "Just… for God's sake, be discreet about it, yeah? If I have to search you, there'll be trouble. Do we understand each other?"

Watson's eyebrows lifted and that chilling calm dissipated as he took the folders. "Right. Yes. Thank you." When he saw that Lestrade was moving for the door, he started to push himself out of the chair.

Lestrade gestured at him to remain seated. "Don't get up, Doctor. I'll see myself out."

He left 221b Baker Street and headed back to the Yard. He had some ballistics files to fudge. God help him.

-X-