The five-star Riverside Hotel has been holding murder-mystery weekends since its opening, but this is the first that security consultant and part-time detective Billie Oliphant has ever attended. Yet, despite its opulent luxury, the hotel has a disturbing history it omits to mention in its glossy brochures. On its opening weekend a young employee, Annabelle Wilder, was found dead in a walk-in freezer. She was naked, bound and gagged - and pregnant. The police have never come close to charging anyone with her murder, despite the fact that at the time of Annabelle's death the hotel only had a dozen or so guests, and security tapes showed that no-one entered or left the building. Billy has been hired by the dead woman's husband to find Annabelle's killer. Opening a cold case is never easy but Billy has a plan. The company that owns the hotel, Amalgam, has arranged for its directors to attend yet another team-building murder weekend. Billy gate-crashes the Amalgam team and offers them the chance to solve a real life murder, knowing full well that any one of these would be detectives could also be a cold-hearted killer.