Doctor Who: The Krillitane Storm by Christopher Cooper

When the TARDIS materializes in medieval Worcester, the Doctor finds the city seemingly deserted. He soon discovers its population are living in a state of terror, afraid to leave their homes after dark, for fear of meeting their doom at the hands of the legendary Devil's Huntsman. And, after a terrifying encounter with a deadly Krillitane, the Doctor realizes the city has good reason to be scared!