A twisted and vicious serial killer is holding the country to ransom, publicly - and gruesomely - murdering his victims. The pattern is clear: a 'calendar killer' is on the loose. On the case is Detective Mark 'Heck' Heckenberg, and he knows one thing for certain: when the killer will strike next. But he doesn't know where and he doesn't know how. With the country's eyes on him, Heck must find the killer before he executes more victims. But it is the murderer who is watching him closest of all.