When Gabriel falls asleep, the first thing that he feels fade through the edges of the dreaming is pain. It flares out, and he follows it only to rush forward as he realizes just who it is that's in pain. She may not want to see him, but if she's in danger, he needs to help.

When he emerges into the chaos of an unfamiliar console room, he looks around, frantic. "TARDIS!" He reaches out with his mind when he doesn't see her human image immediately, and attempts to calm her. This doesn't feel like just a dream, but he can't yet put his finger on why.