The Crystal Bucephalus: a restaurant patronized by the highest echelons of society in the 10th millennium. The guests are projected back in time to sample the food and drink of a bygone age. When the galaxy’s most notorious crime boss is murdered in the Bucephalus, the Doctor, Tegan and Turlough are immediately arrested for the killing. To prove their innocence, they must track down the perpetrators of slaughter and sabotage, and uncover a conspiracy which has been 5,000 years in the making.