You pulled your shotgun over the table, watching and waiting for the sign of someone to peak around the corner. You had your finger on the trigger, and nearly pulled it when a hand wafted over and tossed a cylindrical object into the middle of the room. You were unsure what you were looking at, but Mattis and Karl seemed to react with horror. After a moment, a burst of smoke erupted from the cylinder, much to the relief of both individuals. Adrenaline surged through you again when another loud blast came from beyond the smoke, blowing apart the window behind you and illuminating where the gunman was. He got another shot off before you pulled the trigger on him, nearly deafening yourself as you heard the wood around him split, and heard a wet, gurgling thump onto the floor.
You spent the next few minutes panting, staring through the smoke to where you assumed he was, still holding your empty shotgun trained on them. The smoke cleared enough to see them lying on the floor, clutching their torso, which had a gaping wound gushing blood just under the heart. The trench gun was on the floor next to him, he wasn't even reaching for it, just trying to keep himself from bleeding out. You finally turned your head to see where Mattis was, he was in the floor next to the body, violently shaking it, screaming at it. You had no idea how you didn't even hear him shrieking in grief less than a meter from you. Karl had disappeared by now. You'd killed people. A lot of people. But flying a plane and doing it always had an incredible degree of separation. You'd never shot someone this close. You'd never shot someone with a handheld firearm. It was exactly what you were fearing.
You dropped your shotgun. You'd shot someone, lethally, it appeared. That fact continued bouncing around in your head, strangely emotionlessly. It felt the same as after you went to that first frozen city. You had a lot of feelings about it, but they were being held back by adrenaline. Your teeth started clattering and your entire body started shaking. It was cold, but not cold enough for that. You watched Mattis stand up like an observer to a painting. You knew what he was going to do, but you were unsure if you could stop him.
[ ] Stop him (say how)
[ ] Let him cook.