Mary McGill and her cocker spaniel Millie get the fright of their lives on Halloween when they hear gunshots coming from the bank and the robber, dressed in a clown costume, points his gun at them before fleeing the scene. Mary is horrified when she discovers Police Chief Dan Dunham has been shot in the shoulder and a woman has been killed. Why would the clown shoot an ordinary citizen?Mary soon learns that the victim is Victoria Witherspoon, a local woman who owned a sewing shop and must have recognised the clown costume - because she made it herself. With Dan in hospital and unable to investigate, can Mary and Millie unmask the savage killer clown before he strikes again?