Somewhere off the South Coast of England, there's a lonely island. On that island stands a solitary castle, long since abandoned - haunted, they say. But the truth is, that castle houses something far worse than mere ghosts. The castle is what lies at the end of a trail followed by the Doctor in search of several missing scientists - all of them connected to the top secret Dominus Institute and its elusive CEO, Sir Andrew Gobernar... But the Doctor will soon discover that he's the one being haunted, by a ghost from his past... or perhaps, his future.