The Doctor watches the snake's antics in amusement. What an odd, determined little creature. He always forgets that she has lived on an Earth, albeit a strange one by everything she says. "My planet had red sand too, more orange than this though. The sky was red and the suns were older. Even the grass was red," he says, just as softly. Callie's imprisonment would have been very different from his experience, his flight, but he can't refute some similarities. Is it as bittersweet to her to have left her version of Earth behind, or is she only glad of her freedom? The people one leaves behind probably make a lot of difference. "The architecture was very impressive, of course. Time Lords go in for that, bit much in my opinion," he says candidly, warming to his subject, hoping to draw her out. "But the trees were something to see," more wistfully. The foundation for his castle is good enough, he decides, and starts to work on the center, building up.