Shortly before the bombs drop, high school grad Timothy Campbell (played by Kyle Allen) celebrates getting into UCLA in the kitchen of his home with his mother and fraternal twin brother. Unfortunately their party is cut short when their father rushes in and frantically turns on the TV, informing them of what's going on. Then a group of government officials storms into their home unannounced, and say that they need to take Timothy with them because his genetic makeup hints that he'll be a prime survivor (they got his blood from one of those DNA kits that test family lineage).
He's hauled away from his home as his family looks on in horror and transported to a remote holding cell, where he meets Emily (Ashley Santos). She mentions that they took her straight from jail, where she was locked up for protesting on her college campus; apparently the organisation got her genetic info from the prison doctor and she showed the same signs as being resilient to the impending nuclear Winter. The two of them are then brought across the desolate remains of the LA area to a mysterious subterranean building called "Outpost Three."