Detective Melvyn Stone, that's who. After a mandatory sabbatical in South Africa, Detective Stone returns to duty but this time, he's sharing his body with the ghost of a career criminal! Joined by the ghostly James Wyatt, and his new partner Detective Claire Sanchez, Mel begins to realize the strange journey he is now on. How are he and James linked? What happened to him while he was in South Africa? And what is the significance of the River Styx?