The cast included David Simeon who himself was from Wiltshire where the story was being filmed. He had previously appeared in the "Inferno" story a year earlier. Comedy actress Damaris Hayman starred throughout the five episodes as Miss Hawthorne in a central role. Hayman herself had an interest in the supernatural and helped out during production as an unofficial adviser. A friend of hers was a practicing witch who had commended the scripts for their accuracy. Veteran British actor Robin Wentworth played Professor Horner. Future television presenter and Sooty puppeteer, Matthew Corbett had a brief role in the final episode as a hooded coven member who objects to the sacrifice of Jo Grant, and was suggested to the production team by friend Katy Manning. Other guest actors in the story include Don McKillop as the pub landlord, John Joyce as Garvin and Stephen Thorne as Azal. Thorne would go on to appear in the show again as costumed villains in "The Three Doctors", "Frontier in Space" and "The Hand of Fear".