In the Dubois house, Joe sits in their darkened and disheveled living room. Using a Ham radio, he asks if anyone has seen Allison Dubois, but gets no response. Ariel tells him they're out of food, so Joe goes to look for it in the other houses. Ariel is afraid of being left alone, but Joe assures her she'll be fine. He peeks outside to make sure it's safe, then walks out into their devastated neighborhood. Cars are overturned and burn, debris is everywhere, smoke fills the air. Allison wakes from the dream. Seconds later, an earthquake hits and the family takes cover.
Allison gets a text from Devalos, who wants her to meet him in Chandler. While looking for batteries, Allison realizes they aren't prepared for an emergency and wants to buy earthquake kits. At the crime scene, news crews hover outside the Donlin house. Devalos and Scanlon show Allison the blood-spattered living room. Scanlon shows where he thinks the shooter was while firing the shots. Devalos says it's the same upstairs in their teenage kids' rooms. However, there are no bodies. Nothing was stolen and a background check revealed the Donlins were hardworking, churchgoing people.
At school, Ariel gets a 98% on her geometry test. Behind her, Gavin, a boy she has a crush on, throws his test that he failed onto the floor. Later, Ariel is thrilled when he approaches her and asks her for help in geometry. Meanwhile, at a camping store, owner Russell Burgess helps Allison pick out a large assortment of emergency kits. He says you can't be too prepared. At home, Allison studies the crime scene photos. Joe, sore from hauling everything inside, teases her about the huge amount of supplies that she bought.
That night, Allison dreams of a girl in a bomb shelter. A man in a hazmat suit returns with food after being gone for a week. The girl checks his radioactive levels with a Geiger counter to make sure they're normal, then asks if he saw anyone alive. She sees a can of peaches that he found and is really happy. The man says he found a hospital with plenty of supplies. As he strips off his suit, he tells her that everyone from Tempe to Tucson is dead. When he turns, it's revealed the man is Russell Burgess, the camping store owner.
Allison tells Joe about her dream and how real it was. The hopelessness was awful. Worried that she has seen a forthcoming apocalypse, she's shaken. She mentions seeing Russell in her dream. He wonders if the earthquake spawned her dream, but she doesn't think so. Joe considers that something terrible may be coming and encourages Allison to talk to Russell about survival tips. Next day, Allison visits Russell, who is convinced bad times are near. He suggests that she buy a gun.
Scanlon tells Allison that one of the construction guys who worked on the Donlin house didn't check out. His name is Lloyd Higgins, but he used an alias to hide his violent record. He also has no alibi for the murders. Allison looks at the Donlin file and gets a vision of a man burying a body in an industrial area. She tells Scanlon she thinks she knows where they're buried. Meanwhile, Ariel continues to help Gavin with geometry. He takes out a test he wants help with, saying it's an old one he got from the teacher for practice. He then asks her out on a date.
Allison tells Joe about Russell's suggestion of getting a gun. Allison agrees, wanting to be prepared in case a catastrophe causes societal meltdown. Joe thinks she's nuts and refuses to get the gun, fearful of the dangers of having it in a house with children. That night, Allison dreams that the girl in the shelter is sobbing over spilled pills. Russell calms her. She doesn't want to live like this anymore and hasn't gone outside in a long time. Russell says they have to endure. She asks what's the point if there are no people left. He says they'll make more. He'll be Adam, and she'll be his Eve.
Next day, Devalos tells Allison the body they found by the warehouse isn't one of the Donlins. When they show her the body, Allison is shocked to see it's the girl she's been dreaming about, dead of a slit throat. Allison tells Joe, who sees a bright side in it. If the girl is dead now, it means there is no forthcoming catastrophic event. At school, Ariel realizes the practice test that Gavin gave to her is actually the real midterm test that he stole. She's worried because it means she technically cheated as well, having already seen it. Her friend Ashley tells her not to worry.
Scanlon takes Devalos and Allison to a restaurant that's been closed for two years. A local person noticed a foul smell and called police. He leads them to a sink full of liquefied human remains which he thinks are the Donlins, and thinks sulfuric acid was used to dissolve them. Allison gets a vision of Mr. Donlin being shot and sees that the killer's hands are white. Meaning, the sludge is indeed the Donlins and Higgins, who is African-American, isn't the killer. She relays this to Scanlon and Devalos.
At home, Joe comforts Allison, who is depressed over the total destruction of the Donlin family. She wonders who could do such a thing and says things like that make her wish that someone would wipe the slate of humanity clean. Joe says she doesn't mean that, and tells her to not think about the case.
Allison dreams that the girl in the shelter accidentally knocks over a lantern, triggering a fast-spreading fire. The smoke releases an emergency lock, allowing her to exit. She ascends the ladder and opens the hatch to above ground. To her shock, she sees a plane flying overhead. Down the hill, there's a house with the lights on. She goes inside, where the TV is on and asks if anyone is home. Russell sees her and knows his gig is up. As she points to the very alive people on TV, Russell uses the distraction to sneak up behind her and slit her throat.
Allison tells Devalos about her dream. Scanlon says they'll have an ID on the girl soon. They call Russell into the station and show him the pictures of the dead girl, but he says he's never seen her before. When Devalos and Scanlon say they believe she was held prisoner for a time, then ask Russell if he has a bunker, he realizes he's the suspect. He says he has a bomb shelter that came with his house, but that there was a fire. He invites them to search it.
Ariel confronts Gavin about the test and threatens to tell on him. He tells her that she won't report him because she doesn't want to risk her reputation, and then says that would make things awkward on their date. Angry, Ariel says there isn't going to be a date. Ego bruised, Gavin asks if it's true if she that has that "sixth sense" like her mom. When Ariel says maybe, Gavin sneers that it didn't much help her when it came to him.
Scanlon calls Allison and says he didn't come up with any evidence of a girl being held captive in Russell's burned out bunker. They've identified the girl as Zoey Lehman, whose parents reported her as a runaway three years ago. Later, Allison dreams of Russell telling someone that there's been a terrorist attack and that her dad asked him to take care of her in the bunker. He says it's too dangerous outside, so she can never leave this room. Allison thinks it's Zoey she's dreaming about, until he addresses the girl as Sarah Donlin. Allison wakes, realizing that Russell has a new captive.
The police raid Russell's camping store but don't find Russell or Sarah. Devalos tells Allison that Russell's house is empty as well. They know that wherever he is, he has Sarah with him. They deduce that Russell killed her whole family so no one would come looking for her. An aftershock hits, spilling a can of yellow paint. At home, Allison comforts Ariel about not having a sixth sense when it comes to people they are close to, or want to be close to. She thinks it's a good thing, not having an unfair advantage over the people who mean the most to them.
That night, Allison dreams of Sarah Donlin in the bunker again. Russell enters, tracking in the yellow paint that Allison saw topple in the store during the earthquake. She alerts Scanlon, who sees that the paint has been trodden through, as well as evidence of a hollow area behind a wall. He calls for backup, and they find Russell and Sarah in the hidden living space in his store. Allison and Joe watch coverage of the arrest on the news.