Nathan Stone, a whiskey-loving private detective wakes up in a hospital with a concussion and a memory loss. Unable to remember his attack or days leading to it, Nathan sets to investigate what happened to him together with Nicole Trent, a homicide detective and a former lover. Nathan quickly finds out he wasn't a victim of a random attack but deeply involved in Nicole's homicide case, involving a local pharmaceutical company Witham. When people connected to Witham die mysteriously of a heart attack, they both soon realize there is more to the case than first appeared.