People laughed at John Dee for years, dismissing the astrologer as a madman or a fraud. Then one day a face appeared in his mirror, a face that was not his own. He was given secrets from beyond time: how to mix potions; how to tame the elements; even how to trap a demon. But Dee’s magic was lost, his library ransacked, his spells and hexes stolen. A dread prophecy was made: "the Earth will burn"...

When the TARDIS lands on a Spanish galleon, caught in an unnatural storm, the Doctor, Alex and Brandon are shipwrecked and separated from each other. Between them they must discover who is waging supernatural war - before the planet is pulled apart. What connects John Dee with Sir Francis Drake and the impending attack of the Spanish Armada?