In Vegas, a troubled marriage is locked into a toxic pact. On return to New York, can Liv escape the horrifying consequences of the trip as Detectives Rawlins and Wiseman begin to close in?

Liv's mother Caryl arrives from Wales and brings with her some difficult questions, just as the police are closing in on Liv.

In a chilling conclusion, Liv's toxic pact reaches boiling point with the stage set for a dark showdown nobody could have expected.