Sherlock smiles weakly when John teases him about the sarcasm. He hasn't had much to smile about since being capture, so he'll take what he can get. Even the act on his face gives him a slight biochemical reaction that doesn't actually help, but is slight relief. Much like trying to put out a house fire with a water pistol, really.

He can feel the shift when John starts to move off of his lap. He helps by removing the blanket and giving his friend some counterweight to balance against. It's a good sign that John still needs to urinate. He hasn't done that much since before John was brought into the cell. Dehydration. He'd inevitably pass a few kidney stones if they make it out of this alive.

A fairly full bladder. Part of it from before his kidnap, no doubt.

Sherlock's eyes are on John when the lights go on, simply because he'd been following the sound. He hadn't expected the sudden change, so once more it's an assault to his senses.

"Oh for God's sake, you could at least bring us breakfast first." He's being impertinent, but that's only because he knows these men will give John their worst whether or not he rebels. It's his way to 'laugh in the face of danger' and to put up a brave front when his mood stems closer to petrified. Not for himself, but because he doesn't think John's body can handle much more of this.

"You don't think you should let him die? Do you really think he won't make the same decision over and over again?"

Had he made a mistake in demanding John to be patched up?