A volume featuring thirteen of DCI Ian Forsyth's cases narrated by DS Alistair MacRae. How can a woman under observation vanish without trace? How can half a dozen diamonds not be found in a room where they have been hidden by a thief? Why are the police unable to find a room in which a murder was seen to take place? How is it possible for a woman to be killed in an abandoned factory inside a police cordon and the murderer still escape? How can a killer leave the scene of a murder without leaving any traces in the deep snow around the house? These and eight other abstruse mysteries are solved by DCI Forsyth by the use of logical deduction