Ghost in the Machine

When The Doctor runs into an old friend, who had been previously assumed dead, it's both a relief and terrifying.

Their lives escalate into a whirlwind of passion and mania. Meanwhile, they struggle to uncover the true identities of their sociopathic friend, Art, and his misfit companions. But will the couple be able to survive the combination of their dangerous enemies, their psychotic friends, and their own chaotic lives?

(In order to understand anything in this book, you must read the first book: The Last of Gallifrey)