"Right," Sherlock said, committing all these details to his memory. "I'll find him."
He backed out of the control room, mind racing. He hadn't allowed much contact with the other versions of the Doctor. From what Sherlock had observed, the other Doctors did communicate with each other, even if they were occasionally in conflict with themselves. But they had all distrusted this other version of themself.
Sherlock could only reach one conclusion, and that this Time Lord was not the Doctor. Whoever he was, it was possible he'd caused this explosion as a diversion. Either way, he wasn't likely to put himself in danger. He hurried down the hallways, moving away from the chaos and down, deeper into the bowels of the ship.
He moved as quickly and quietly as he could, wishing he had John's gun. He knew he couldn't kill the man, but it would have been nice to have it.
He grinned when he reached a level with a very fine coat of dust on the floor. Wonderful. He found footsteps, and followed them eagerly, weaving his way through the corridors. He must be getting close now. He slowed down and moved more cautiously, keeping an eye out for any sign of movement.