The Doctor gets very interested in the happenings at the Devil's Hump, the site of an archaeological dig. He learns of it thanks to the coverage of the dig by a news team from BBC3. The Doctor suspects that Professor Horner, who is in charge of the dig, may unearth something that might cause quite a bit of trouble. The fact that the professor has chosen to do said unearthing on Beltane (May 1) seems to increase the Doctor's anxiety. He rushes with Jo Grant to get to the site of the dig before midnight, when Professor Horner plans to break through a wall that has remained intact for thousands of years.
Miss Hawthorne, a local white witch, also fears that the Horner might cause problems with his stunt. She turns to the local vicar for help. The Master, disguised as the vicar, tries to hypnotize her but her abilities prevent him from succeeding in that venture.





