When the circus arrives in Edinburgh, Rose McQuinn is delighted. However, the festivities are overshadowed by the murder of a clerk during a bank robbery and the suicides of two young women. Are these deaths straightforward or could they all be linked to one killer? Rose's ex-fiance Inspector Jack Macmerry believes that Rose can help with his inquiries and she finds suspicious links with the circus and the behaviour of a sinister scar-faced clown. Rose cannot prove conclusively who the real killer is. She confides in her new-found friend - young, rich and beautiful Elma Rice - and together they sift through the circumstantial evidence. But when there is a murderous attack on Elma's husband, Rose must discover what vital clue she overlooked.