What could make a successful, happily married man like Eliot Martagon take a gun and shoot himself? What made Theo Benton, a young artist on the brink of fame, throw himself to his death? As they are both suicides, officially they do not require the attention of a high ranking officer, but Chief Inspector Lamb's curiosity pays off when a post-mortem reveals surprising results. As Lamb looks for links between the two men, all paths lead to the enigmatic figure of Mrs Isobel Amberley and a mysterious event that took place one winter's night in Vienna...an event with devastating repercussions.