Another of the author's heavily detailed police procedurals (The Hanging Tree) featuring Superintendent Colin Thane. Vacationing policewoman Mary Dutton has been found dead at the foot of a cliff near remote Glen Torbat Peace Camp, where she's been staying. The original report of accidental death, though, is soon changed to murder by super forensic-pathologist Professor MacMaster--and Thane's squad is on the hunt. The camp, a kind of primitive motel managed by Peter Crossley, inherited by Barbara and Magnus Thornton, seems innocent enough. Thane concentrates on a cryptic postcard sent by Mary to a friend, pointing to something connected with past police work. Eventually, dogged sleuthing turns up a pair of suave con men--specialists in forged checks and stolen credit cards--whom Thane tracks down. . .only to find two more murder victims. Something big is afoot! It takes forays into Glasgow's seedy underworld, past rescue work by Jock Dawson and his trained dogs, the sharp eyes of Detective Sandra Craig and a final showdown in Glasgow's Burrell Museum before the case is nailed down. Competent and mostly absorbing, this is one of Knox's better efforts.