The side of Sherlock's head finds the ground and he closes his eyes. Or he thinks he does. It's hard to tell when the surrounding area's pitch black. Hope somehow hasn't left him entirely, so he clings to that last bit of hope that his physical and mental states are giving him a hallucination.

This can't be John. Moriarty has used him against me before. But not like this. He wouldn't. He couldn't. Oh, but he would. This is exactly something he would do.

John's response confirms it. Hearing his voice, slurred as it is, makes everything fit into place. Acoustics, tone, accent. All pointing toward the one centre point of John Watson. That, and the choice of words and focus. He'd been drugged and thinks this is a hallucination.

"No," he mutters. No! He has to be careful. They could be listening in. He has to remain at least somewhat detached or Moriarty will know how strong his Ace of Spades really is against him. He already knows

"John, it's really me. You're not hurt?" Sherlock asks him, trying again to reach his hand toward his friend's voice. The sound of his chains clanking and then coming to a sudden, snapping halt that can be heard quite easily. This time Sherlock just grunts from the pain before futilely trying to pull his hand free.