The TARDIS rumbled for a moment as Ace activated some of it's systems. They hummed and powered down as the particular sequence needed to use it was not followed. It was good to have Dorothy home, and as the humans would say : even though they weren't in Kansas anymore. "It was time to change the TARDIS, it grows, and evolves Ace."
The Doctor grew silent for a moment remembering. "I do not think the Master has anything to do with this place, Ace. I have not seen him in a long, long time. I think his time may have run out. The TARDIS can move, oh yes wonderfully. What we cannot seem to do is leave the City." he paused. "yet."
Ace's last question hit the Gallifreyan like a ton of bricks. There should be someone with him. Someone trapped in another dimension forever. "Ah There should be Ace, there was, then was not, then there is again." He smiled his enigmatic smile and put a hand on a lever of the control module. Green mist flowed underfoot as the time ship came slowly to life. "I have some friends here in the City, New and old. We could try to work together. If you want to take another journey, that is."
The door was still open, but the ship was definitely powering up.