In a chilling conclusion, Liv's toxic pact reaches boiling point with the stage set for a dark showdown nobody could have expected.
Liv's mother Caryl arrives from Wales and brings with her some difficult questions, just as the police are closing in on Liv.
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 wakes to the crushing realisation of what she has done. The need for an alibi is crucial, but as a search mission begins, there is a nightmarish surprise waiting at her door.
An envious apartment in glamorous New York, an intensely passionate marriage, and the promise of the perfect life together, British newlyweds Liv and Will are living the American dream. But a chilling secret unravels the fairytale. Can the trip of a lifetime to the American Wilderness save their marriage?