Melissa Townsend is young, rich, attractive and has a superior attitude that is most off-putting. She is generally disliked by almost everyone in the village and Barnaby is called when she starts to receive threatening letters. Soon after a break in at the local vets, Melissa is found dead, having been injected with a deadly substance. Among the suspects are Melissa's friend Sally, the vet and several other villagers. The police's biggest problem is that they start to run out of suspects as, one by one, they too are murdered. In the end, the solution revolves around blackmail and someone's desire for social acceptability.