"She's crippled." It hurt the Doctor to even say it, but it was true. His magnificent ship was crippled, and he had no idea how to fix her. "She can't travel in time or space. She's trapped here until we can find a way to fix her. Something happened to her, something terrible, and we're still not certain what. I'm sorry, John, but you're going to have to find a way to cope with being here right now. There's nowhere else to go."