Anonymous:

"This story takes place just before the ordeal of losing Rose to the void, which afterward the Doctor did not want to continue on living. They were floating about space somewhere, having a right good chat when the Doctor suddenly became very serious. "Oy, what's gotten into you?" Rose asked curiously, but as soon as she asked he was hopping about the TARDIS like nothing had happened. His mind was set now, "Alright," she said, "I'll go along." She smiled and then they were off to somewhere new."