Prisoner of the Sun

Six years after being captured by the galaxy-spanning organisation known only as The Consensus, the Doctor lives inside a hi-tech complex at the heart of an unstable sun, condemned to an eternity maintaining its systems. A moment's carelessness could cause the star to collapse—and the deaths of billions. Watched over by liquid guards, the Mercurials, the Doctor's only company at the heart of the sun is his assistant 'Daphne'—the latest in a line of android helpers. But rebels have their eyes on the sun, and its lonely controller—and are prepared to risk even a galactic cataclysm to secure the Doctor's release...