Beth (Vinessa Shaw) and Francis (Ebon Moss-Bachrach), a young married couple, are on holiday together when they venture to a beautiful, but highly remote, island. Beth is pregnant and the two are hoping to enjoy their last vacation before their baby is born. When they arrive, they notice that while there are plenty of children present, the adults all seem to be missing. Initially attributing this to the after effects of a recent festival, they quickly realize something far more sinister is afoot. The two will face terror and unsettling difficult decisions in their quest to make it off the island alive.