Love is the strongest emotion. It can bring people together but it can also drive them apart. For love can become twisted and evil. And, if obsession, jealousy and suspicion take hold, all other feelings can be prevented and sometimes lead to murder. In this disturbing catalogue of bloody valentines, crime writer and journalist Douglas Skelton delves into the darker side of Scotland's psyche to uncover chilling crimes of passion where love turned sour and the outcome was lethal.