Dave (Joel Edgerton) and Alice (Felicity Price) are about to become new parents when they agree to join Alice's little sister Steph (Teresa Palmer) and her new boyfriend Jeremy (Anthony Starr) on a sun-soaked trip to Cambodia. But their tropical retreat quickly turns sour when Jeremy vanishes without a trace. After investigations fail to shed any light on the disappearance, Dave and Alice return home to their young family desperate for answers. When Steph returns not long after, a brutal secret is revealed about the night her boyfriend went missing. But it is only the first of many.