Eric (Jonathan Groff), Andrew (Ben Aldridge) and their seven-year-old daughter Wen (Kristen Cui) are on holiday at a remote cabin in the woods when four strangers appear and inform them that they need the family's help to save the world.

After taking them hostage, Leonard (Dave Bautista), the group's leader, warns Eric and Andrew that they will need to sacrifice one member of their family to avert a looming apocalypse. Will they make a decision before it's too late?