Two couples disappear in the tiny village of Monks Barton amid rumours of witchcraft and haunted woods. As Barnaby and Jones investigate, psychic Cyrus LeVanu clashes with cleric Wallace Stone over their different methods of `healing' the woods, while other locals seem to be caught up in a stolen antiques racket. When a body is unearthed and the death toll rises, the detectives race to find a connection between the missing couples and the thefts to catch the killer.