On Christmas Eve, Georgia Olsen (Chloe Grace Moretz) finds out that she is pregnant with her boyfriend, Sam Hoth's (Algee Smith), child. The new revelation disturbs her peace, as she doesn't want to become a mother at this age. Sam tries to console Georgia and asks her to marry him, but she is unsure about the relationship. Georgia decides to hide the secret from her parents (Father (Jon F. Merz) & Mother (Tamara Hickey)). In a hurry, she leaves behind her phone and walks out of the house to attend a college Christmas party. An android, Eli (Stephen Thorne), owned by the Olsens, wishes Sam happy Halloween instead of Christmas, thus signaling that something is wrong.At the party, people hear a shrill screech, similar to a technical glitch, and soon after, an android named Daniel (Liam McNeill) turns violent. He attacks Georgia and Sam, and they run away from the house. Due to the glitch, smartphones start exploding, killing their users. On the streets, Georgia and Sam witness the doom. The androids launched an EMP attacks to bring down all electronic defenses and destroyed NYC. Nine months later, Georgia, expecting her baby, has taken shelter in the forest with Sam. The couple are trying to get to a fortified Boston. They have heard rumors about a boat that is transporting new mothers to Asia, where they can find a peaceful life. Boston is surrounded by a no-man's land full of Androids.They avoid all roads and travel through the woods, until they reach a military camp. While Georgia gets examined by a Doctor Howe (Kate Avallone) (who informs her that the baby is way past due and that Georgia should not be travelling at all) (The doctor also tells Georgia that the boats are now only taking babies and mothers, no fathers due to scarcity of food for the crossings), Sam tries to find out how to reach Boston. Georgia wants to deliver at the camp, where they have shelter, but Sam says that crossing the no man's land with a baby will be impossible, so they need to get into Boston before the baby arrives.At night, he gets into a fight with one of the soldiers (The soldiers were high and, in a campfire, when Sam inquired about a ride to Boston. A convoy was going up to Nashua the next day, but one soldier challenges Sam to a fight for that ride), and he and Georgia are expelled from the camp the next day (Sam busted the soldier who is going to blind in one eye). They continue on, until they find an abandoned house, where they spend the night. They can travel way up north and find a boat back into Boston Harbor. This is safe but will take 2 weeks. Or they cut straight through No Man's land for 20 miles and reach Boston within 2 days. Sam finds a motorcycle and fixes it up. Sam wants to go straight through even though the bike will create noise and attract attention from Androids. Sam argues that once the baby arrives it will be noisy as well, so they may as well take their chances now.The following day, the couple are able to travel much quicker on the bike. While stopped at a river, they are spotted by an android, who pursues them. Soon, several more androids give chase, accompanied by drones. Sam drops off Georgia and tries to lure the androids away on the motorbike. Meanwhile, Georgia meets a camouflaged man who offers to help her. He turns out to be an AI programmer who tells her that the androids have learned to hack their own software. He introduces himself as Arthur (Raúl Castillo). Arthur tells Georgia that Androids want to wipe humans off Earth and warns her to forget Sam. Arthur is very emotional about Georgia's coming baby.In the morning, Georgia awakes to contractions. She tells Arthur that she needs to find Sam, and he leads her to where her partner is being held. They approach a building patrolled by androids, from which cries of pain can be heard. Arthur gives Georgia a camouflaged vest, which he claims will conceal her. She walks through the building, looking for Sam, unseen by the androids. She finds him in one of the rooms, with his legs badly broken. While she is freeing Sam, another prisoner tries to draw the attention of the androids. Georgia drags Sam out into a large garage. She collapses from contractions, and just as they are about to be apprehended, Arthur intervenes, stabbing an android and saving them. Georgia goes into labor in Arthur's truck. She wakes up in a hospital clinic, with Sam beside her. A nurse informs her that the C-section delivery went well, and that they have a baby boy. The couple name their son Forest. Sam has had both of his legs amputated.Later, Georgia gets questioned by a security officer. She tells him what she and Sam have been through and mentions the vest that allowed her to avoid detection by androids. The officer tells her that such technology doesn't exist. Georgia then realizes that Arthur is an android and that he deceived her to gain access to Boston. Within moments, the power goes out, and the base comes under attack. Georgia tries to wake up Sam, to no avail. She heads down to try and activate the base perimeter and is confronted by Arthur. She shoots him in the face repeatedly, killing him. She manages to activate the EMP pulse, thereby killing all the Androids and returns to Sam.When Georgia wakes up again, Sam is up, and together with Forest, they head to the harbor, where Korean officer (Hana Kim) are loading a boat headed to Korea. They are only able to take Forest, however, as Georgia and a legless Sam are useless to them (they are another mouth to feed and in Korea they will need a job and a house). After pleading with them to no avail, Georgia is convinced by Sam to let Forest go and have a better life.