Arriving in Victorian London, the Fifth Doctor, Nyssa and Tegan run straight into trouble: Nyssa is kidnapped in the British Museum by Egyptian religious fanatics; the Doctor and Tegan are greeted by a stranger who knows more about them than he should and invited to a very strange party. Why are rooms already booked for the Doctor at the Savoy? How can Lord Kenilworth's butler Atkins be in Egypt and London at the same time? What is the history of the ancient mummy to be unwrapped at Kenilworth's house? And what has all this got to do with Nyssa?