After being dragged through a rip in the time vortex, the TARDIS returns the Doctor, Sarah and Harry to Earth. They are in medieval times, but something strange is afoot. The villagers live in fear of the sinister Brotherhood, an order of monks that upholds the sacred laws. Then there’s Faustus Black, with his troupe of travelling players. What connects them is a terrible secret hidden in the Forbidden Forest, a cave from which nobody has ever returned.