 The Doctor takes Ace to Gabriel Chase. An old Victorian house which stands in the teenage s home town of Perivale. But the location and the name of the house is unknown to Ace as the Doctor has an ulterior motive for bringing her to the sinister building. As they make their presence in the house known to those who reside within It s walls. The Doctor and his companion discover an odd assortment of characters. Josiah Samuel Smith, an ambitious and ruthless man, who is not what he seems. Redvers Fenn Cooper, an eccentric explorer who saw something in the cellar of Gabriel Chase and has gone mad as a result. Josiah s Butler Nimrod who strongly resembles a Neanderthal. The stern housekeeper, Mrs. Pritchard and Josiah s pretty but unusual Niece Gwendoline. And then there is Control. A  depraved monstrosity  as Josiah calls her. A poor, deprived creature that is kept locked away in the Cellar of Gabriel Chase. Along with what seems to be a large stone spaceship which contains an alien life-form that has been asleep for centuries. All are connected to Gabriel Chase in some mysterious way. And to events that will take place in Ace s personal past. And a hundred years in the future.