There are times when James Moriarty enjoys playing at being dead. Sebastian will come home to a dark flat to find him curled into a ball, precisely placed just out of sight from the door, after administering a drug that renders his heart rate almost imperceptible. He lays there, doesn't respond to any stimulus until he grows bored with this stage.
The first time this happens, his precious little trained killer cusses, drops his weapons, and is checking his pulse in seconds, then demanding to know what's going on. He keeps it up for two or three minutes before he gives in to the impulse to giggle. The first time just so happens to be the second day that Sebbie is in his employ, and not entirely aware of what the rules are, so his giggling is rewarded with a slap in the face, and in seconds Jim is off the floor snarling, pausing only long enough to calculate where he could stab the other without causing too much permanent damage.
Moran yells in shock, balls his bleeding hand into a fist, and tries to bury it in Jim's stomach. He sucks in his stomach, taking only the barest edge of the punch and returns it with two fingers jabbing the bundle of nerves that will paralyze the arm. He follows up with quick stiff-fingered jabs to the other's occipital muscles, driving his fingers up almost under the skull, then knees him in the groin, stepping back to allow Seb to crumple to the ground without touching him.
He waits a moment, then crouches and whispers "Not. The. Face." Before pivoting and walking off, giggling.