Muscle memory. It was a hell of a drug. One neuron fires its bullet down a chain and all of a sudden you're back in a fight, your muscles striating the skin with how hard you're straining, the tendons in your neck jumping out and snapping like bridge suspensions.
Trying to breathe, now that's a joke.
Catching your breath even as your lungs buck and kick against you, refusing the spinal cord communication like a cat turning up its nose at a food bowl, have you ever tried that? Wrestling with your own body?
The point is, muscle memory. The point is, nightmares.
He brings his hand up to his face. No blood. He feels down his side. No blood. He licks in between every tooth and only when he is sure there's no blood, nothing there other than yesterday's dinner, only then can he relax. He presses his face into his hands and sighs. With the moon right above him, he looks old and silver, just another American Gothic in greyscale.

In the bruised dark, you feel more than you hear or see. He tenses at the touch at first. Old habits, they die like cockroaches— which is to say, they don't really die at all.
They sit there for a while, one pale and one dark, and he can feel the overlap where their shoulders touch, and then their sides, all the way down to their legs and feet. Warmth. The chemical reactions inside Evien eat up food and oxygen. Inside, catalysts and enzymes are ripping sugar chains apart into blazing sparks of energy but outside, it's so quiet. 
It's so still.
Hey, he lets his head fall onto Evien's shoulder. You couldn't sleep? Then, Me too.
They nurse the silence like a cigarette being passed between two pairs of hands. One drag, one drag at a time.