Deep in the mine, Lana struggles against disorienting gas and the gaiaphage’s commanding voice. The entity, a mixture of human and alien DNA, appears as millions of tiny, glowing green crystals. It forces her hand onto its surface and reveals its plan: Once fed with more radiation, it will use her healing power to build monstrous bodies within bodies—like nesting dolls—so it can escape the mine and destroy any who resist.

In town, Sam learns from Taylor that Mickey is dead but Mike escaped, leaving Caine without hostages. A house fire breaks out when a child accidentally starts a blaze; Fire Chief Ellen contains it. Brianna appears, alive but injured, and demands an attack on Caine. Sam, weary and despondent, refuses, citing growing conflict between “freaks” and “normals.” He reveals that Lana is missing.

Albert and Quinn confess to Sam about their mission with Lana and Cookie to get gold. Sam barely reacts. Albert sends Quinn fishing and begins melting gold bars at McDonald’s. He uses a bullet mold and produces 224 gold bullets over 10 hours. Running low on fuel, he plans to ask Sam for help and designs a new currency system using gold slugs and McDonald’s Monopoly game pieces as smaller-denomination tickets.

Caine secretly assigns Bug a mission: find Orsay, who can see dreams, at Coates Academy and bring her to the mine to discover what the gaiaphage plans for Caine. Bug turns invisible and slips away undetected.

Walking toward Coates, Bug stops at the grocery store Ralph’s, where he finds kids secretly butchering fish in the storeroom. Quinn arrives to discuss the catch. Desperate with hunger, Bug reveals himself and offers information about Caine’s plans in exchange for fish. Quinn calls guards and sends for Sam and Astrid but gives Bug one bite.

Sam hides in his old bedroom, overwhelmed by his failures and responsibilities. He imagines facing a tribunal that accuses him of neglect and the children resorting to cannibalism. Astrid finds him and reports that Bug has defected: Caine sent for Orsay to learn about the gaiaphage, and Cookie returned with Lana’s letter. Sam tells her to handle it herself, and they argue. He accuses her of manipulating him into leadership to protect Little Pete, then breaks down completely, screaming about the unbearable pressure and confessing he wants to die to stop thinking. Astrid holds him until he calms. Ashamed, Sam asks her never to tell anyone and not to comfort him again, fearing he will break. Finally, he asks to hear what is in Lana’s letter.

Hunter hides in an abandoned house, starving after being chased from town by Zil’s friends. He considers letting himself disappear when he turns 15 in two days. Spotting a doe in the backyard, he kills it with his heat powers and, despite overwhelming guilt recalling his accident with Harry, butchers it out of hunger.

At Coates, Orsay is also starving and recalls an incident where a girl was beaten up and robbed of her mushrooms. Orsay notices more kids joking about cannibalism. Bug appears, gives her a bag of fish, and explains she must use her power on a creature in a mine. He tells her they are currently working for Sam’s side because Sam has fish, and that they only need to walk to the highway, where someone will meet them with a car.

Sam, Astrid, Edilio, Brianna, Taylor, Quinn, and Albert gather at Astrid’s house to hear Bug’s story. Astrid reads Lana’s letter, in which Lana says she is attempting to kill the Darkness. The group agrees they need Orsay to learn about the gaiaphage, and Edilio is assigned to take her to the mine.

Edilio drives Bug and Orsay toward the mine following Caine’s map. At the ghost town, Orsay suddenly screams for them to stop, is seized by violent convulsions, and begins biting her own tongue. Edilio forces a tire gauge between her teeth as coyotes attack the Jeep. He shoots one and speeds away, escaping the pack. Orsay explains the creature ordered her to bite off her tongue to prevent her from warning them. She reveals it is hungry, that food is coming, and that once fed it will use the Healer to build itself a body—unstoppable once transformed.

At home, Little Pete repeats the phrase about being hungry in the dark. He says Nestor the nesting doll is afraid, then adds that the entity has Lana, before falling asleep. Astrid lies beside him, beginning to connect the puzzle pieces.

Jack tells Caine he can extract a uranium fuel rod but must first shut down the reactor completely, cutting all electricity in the FAYZ. He warns of lethal radiation danger if the lead-lined sheath is damaged. Caine decides to wait for dark and move overland, assigning Drake to create a diversion. Diana confronts Caine, warning him that Bug has defected and that the gaiaphage will use and discard him.

In town, Astrid presents her theory to Sam and Edilio: the gaiaphage is a life-form that arrived on a meteorite thirteen years ago, fed on radiation, and caused the children’s mutations. She believes it is running out of food and tried to cause a meltdown, which Little Pete stopped by creating the FAYZ. Now Caine will feed it uranium, which it will use to build an invulnerable body. Little Pete says the name Nestor.

At Zil’s gathering, his Human Crew complains that “freaks” are hoarding food. Hank announces he has found Hunter across the highway with a deer he killed using his powers and proposes killing Hunter. Zil, uneasy with the thought and afraid that he has lost control over his group, takes Turk’s idea to hold a trial instead. Turk suggests finding a way to identify who is and isn’t a mutant.

Drake positions himself at the hole in the power plant wall, waiting to create a diversion. Howard suddenly appears and yells in surprise. Drake fires but misses. Dekka flies up using her power, causing Drake’s shot to go high, then falls hard to the ground. Drake takes aim for the killing shot. Orc throws a motorcycle wheel through the wall hole, knocking Drake down, then Drake fires blindly and flees as Orc tries to grab him.

Hearing the premature gunfire, Caine forces Jack to begin the reactor shutdown immediately. Jack lowers the control rods and the turbines wind down. Caine, Diana, and Jack enter the reactor room, where Jack starts the extraction sequence. Impatient, Caine hurls a forklift through the containment dome to create an exit.

Zil’s Human Crew sneaks up on Hunter’s house. Lance approaches as a distraction, offering help skinning the deer, while the others rush Hunter from behind. Hank knocks him unconscious with a crowbar. They bind and cover his hands, devour the deer meat, then prop up the semi-conscious Hunter and hold a mock trial. Zil pronounces him guilty. Hank is eager to execute Hunter instead of letting him go. Zil, caught between looking weak and starting a war with Sam he knows he will lose, devises a plan to use the deer meat to rally hungry “normal” kids, creating a force too large for Sam to oppose.

Sam and Edilio arrive at the power plant to find Dekka recovering. Howard explains that Drake shot at Dekka and Orc saved her. Hearing a loud boom from inside, Sam orders Edilio and Dekka to seal the mine and sends Howard and Orc back to town to keep order and send backup. He will deal with Caine himself. When Edilio objects to Sam going alone, Sam names him his successor if he dies.

Inside the dome, Caine goads Drake into confronting Sam by suggesting Diana could manipulate Sam instead. Drake agrees to face Sam and vows to bring back Sam’s severed hand as a trophy. Caine then telekinetically launches the 12-foot, lead-sheathed fuel rod through the hole in the dome and out onto the hillside.

Sam, feeling strangely at peace, enters the silent plant and finds Drake waiting in the reactor room. Drake reveals a remote control and triggers an alarm as control rods begin rising from the reactor core. He explains that full withdrawal will cause a meltdown. Holding the remote over the reactor pool, he threatens to drop it if Sam attacks, forcing Sam to stand still as Drake brutally whips Sam to his knees. Brianna appears and uses a wire to slice off 18 inches of Drake’s whip arm. Stunned, Drake drops the remote toward the reactor pool. Sam yells for Brianna to catch it; she dives and grabs it inches above the water, pushes off the rising control rods, and skids across the floor. She rushes to Sam, who gasps for her to press the red button, and the alarm stops.

At her home, Astrid finds Mary unconscious in the bathroom. She discovers ipecac and laxatives and realizes Mary has an eating disorder and is starving herself. John helps her take Mary to see Dahra for medical treatment. He mentions that Zil is offering deer meat to any “normal” who helps punish Hunter.

Edilio and Dekka hike up to the mine entrance, fighting oppressive fear. As Dekka raises her hands to collapse the structure, Lana emerges from the mine in a trance and, in an inhuman voice, orders them to stop.

As Brianna treats Sam’s wounds, the pain is so severe she injects him with morphine. Losing consciousness, Sam tells her she was exposed to radiation and must find Duck and take him to the mine to deal with Lana.

Brianna races through Perdido Beach searching for Duck and runs into Astrid, John, and Little Pete pulling an unconscious Mary Terrafino in a wagon. When Brianna says Duck’s name, Little Pete repeats it, prompting Astrid’s realization. Brianna breaks down telling Astrid how badly Sam is hurt. Just then, Zil’s procession arrives in the plaza with the deer and Hunter on a rope. A mob rushes toward Brianna. Astrid tells her to ignore them and do what Sam said; Brianna draws the mob away, taunts them, and easily escapes.