Mercy

John's heart stopped. He was in Jim Moriarty's house. He clenched his jaw and squeezed his eyes shut, trying to get ahold of himself as the dark-haired Irishman walked into view.

"Cambridge and Hatsfield are dead, I presume?" he asked, setting the scotch glass down and looking towards the fire.

"Yes," Sebastian said tersely. He forced himself to sit down and look calm. Jim would be able to see through him in a second if he showed any sign of nervousness. God, if Jim knew he was dating someone, Sebastian would never hear the end of it. "I was just settling in for a relaxing evening. I thought I'd polish my guns...maybe sharpen the old Bowie knives…" He tried to make his evening sound as dull as possible.

The ploy seemed to work. Jim rolled his eyes. "Dull. Well, I've got work to do—meeting with the Iranian Ambassador tomorrow. Good for nothing, incompetent moron." He sniffed dismissively and brushed a hand through his hair, slicking it back a bit. "I'll leave you to your devices—shoot another hole in my wall and I'll have you castrated. Also, remember that you have a job tomorrow afternoon. I'll leave the file on my desk." He brushed off a shoulder of his suit and turned back towards the door, exiting.

John was crouched over, his hand clamped over his mouth during the entire time Jim was in the room. When he heard Jim leave, he stayed frozen, although his heart was hammering against his chest. What did this mean? Had Sebastian tricked him this entire time? Why? John didn't know which emotion had taken the forefront of his mind: fear, confusion, hurt, or rage.

He heard Sebastian heave a sigh. "John? I'm so sorry about that. You can come out now. My boss...I wasn't expecting him to come back so early." He walked over to where John was hiding.

John felt like a caged animal as he looked up at Sebastian with entirely new eyes. He backed against the wall, still crouching. "Jim Moriarty?" he finally spat out. "Jim Moriarty is your 'boss'? What the hell is this? A trap? A trick? Is this the part after you lure me to your place and then slit my throat?!"

Sebastian's jaw dropped open, then he narrowed his eyes and yanked John to his feet. "How do you know Jim Moriarty?" he hissed, not wanting Jim to hear through the wall. "That's not a name that gets tossed around! Who are you?!"

John jerked as Sebastian yanked him upwards, suddenly not finding the man handling sexy so much as terrifying and he shoved himself away from him and took a step back towards the door. "I don't know what your game is, but you stay away from me, and you stay away from Sherlock!"

"Sherlock Holmes?!" Sebastian had to fight to keep from raising his voice. "You know Sherlock Holmes?" This was too much.

"Hilarious!" John spat in disdain. "I talk about my genius flatmate and how I help him with crime solving on Baker Street, and you conveniently didn't put the pieces together? Stay away from me." John cast Sebastian a look of loathing and turned to walk out.

He didn't even know if he could get out of the place, but he was sure as hell going to try. How could he have been such an idiot? Sherlock would've deduced who this man was by day one. John had never felt more stupid, more hurt, or more betrayed in his life. He had liked Sebastian, he really, really had. He should have known it was too good to be true.

"John, you can't just leave," Sebastian said. He was completely conflicted. What were the fucking odds? He would have to kill him. John knew where Jim lived, and with how mad John was now, there was no way he was going to keep it a secret from that nosy detective he was cozied up to. He strode over to John and yanked him away from the door. "I'm sorry, John." And he was, even as he looked down darkly at John, preventing him from leaving. Why did it have to be this way?

"Between Jim and I, there's no way you're getting out of here alive." Usually when he said things like this to someone he had a gleeful smile on his face. Now he just felt awful. He didn't want to kill this man, despite everything. But John would tell fucking Sherlock Holmes everything, and that would be the end. That couldn't happen.

John's stomach dropped. So this was it, then. The man hadn't even tried to deny his role with Moriarty. Here he'd gone, opening his vulnerable heart up to Sebastian—stupid, stupid! Would Sherlock mourn his death, or would he just shake his head at what an astounding idiot John had been?

Sebastian had locked the door and had picked up the Browning he'd been showing to John earlier. His exterior was calm as he loaded the bullets into the catridge, but inside he was in turmoil.

John looked around the room for some way of escape. He could fight—military service had given him that, but Sebastian was more experienced and far larger. And armed. John clenched his jaw. All the cards were against him.

"I'll have to explain the mess to Jim somehow," Sebastian muttered aloud, more to himself than anything. He'd need to think of some story that didn't involve him being duped into a date by Jim's rival's sidekick.

"Yeah, well, I can't really say I feel for you," John said coldly.

Sebastian attached a silencer to the gun and trained the barrel on John's forehead. "I really did like you, you know…"

John closed his eyes and took in a deep, unsteady breath. He wanted to stay calm, to die fearless. He didn't want to go out like this, betrayed, emotionally wounded, with tears threatening to fall and a knot at the pit of his stomach. "Shut up—just...just stop acting! You've won, just do it," he choked out. He squeezed his hands into fists and forced himself to open his eyes and stare past the barrel at Sebastian. It wasn't fair, he thought. He'd survived a war, only to come home, meet someone he really liked and then have them kill him. It was twisted. "...Just do it...' he murmured, his blue eyes locking with Sebastian's gray ones.

Sebastian stroked the trigger with his finger. One flick and it would be over. John was right—he needed to do it. When John met his eyes, though, his finger wouldn't budge. Cursing under his breath, he stepped back, keeping the gun trained at John. "Now listen carefully," he said, his voice low and taut. "I am going to go out of this room. When you hear a gunshot, you leave this room, get outside and hail the first cab you see. You will stay the fuck away from this place, and if you breathe a word of this location to Sherlock, your life is mine. Got it?"

John stared at Sebastian in disbelief, then at the gun barrel as it lowered to the carpet. He was going to let him go? Why? Did he want a moving target? "You're letting me go?" he asked aloud.

"Yes, dammit," Sebastian said through clenched teeth. This was disgraceful. He was weak, not being able to kill someone who posed a known threat. He gave John a final look. He wanted, as idiotic as it sounded, to be able to see him again, but this would likely be the last time. It had better be the last time—he didn't want to be faced with the prospect of killing this man. "Goodbye, John," he said, then disappeared out the door and went upstairs and promptly fired a bullet into the bathroom wall. That would distract Jim for a while. He hoped to God John was running for the door, and he also hoped that Jim didn't keep his word on castration.

As soon as John heard the gunshot, he slipped through the door, and silently and quickly made his way to the front door, heading out and quietly closed it behind him. His heart was pounding in his chest. Maybe it had been real, then? Why else would Sebastian let him go? Why hadn't he just shot him?

John's head whirred as the cab sped back towards Baker Street, and he still felt shaken when he climbed the steps. Sherlock wasn't there, and it was just as well, John didn't wanted to be bombarded by a barrage of questions he didn't want to answer and didn't know how to. So, he went immediately up to his room, and curled up into his bed, only taking the time to remove his shoes and jacket.

Sebastian forced a grin as Jim stormed in, furious. "I saw a roach, boss."

"You fucking piece of shit!" Jim growled, examining the hole in the wall. "What the FUCK did I tell you?! I swear to God if I didn't need you for that hit tomorrow, I'd slice your balls off and shove then down your throat—NOW GET OUT!" he roared, eyes black with malice.

Sebastian obeyed gladly. He'd gotten off easy. Thank God he had a job tomorrow. He wondered if John had made it back safe, then immediately chided himself for thinking of him. The man was the enemy. He just hoped he kept his mouth shut.