"I think they've forgotten the 'gravity' of the situation..."
As the gravity in the ship failed, the angels began to fall into the crack in time. Just a moment too soon, the Doctor lost his grip and fell into it with the angels.
Moments later, with her eyes still closed, Amy realized that he was gone, and worried. "Doctor? Where have you gone?"
A voice that didn't belong to the Doctor answered. "Doctor who?"