Clay's Ark

An astronaut, the sole survivor of the starship Clay’s Ark which was destroyed five days earlier, wanders the desert. Driven by hunger, thirst, and enhanced senses from an alien microorganism, he fears human contact. He knows the organism compels him to infect others, an act that could prove fatal to his victims, especially women. He walks for nights, seeking food and water but hoping to avoid people.

In the present, Dr. Blake Maslin, an internist, is driving his sixteen-year-old twin daughters, Rane and Keira, home to Palos Verdes Enclave. Keira is dying from acute myeloblastic leukemia. A sandstorm forces them to pull over, where two men, Eli and Ingraham, ambush their Jeep Wagoneer. Though the men appear ill, they possess inhuman strength. They kidnap the family, separating Rane into a red Mercedes with a woman named Meda Boyd. Eli drives the Wagoneer with Blake and Keira, who he reveals has been awake and concealing a screwdriver.

In the past, the astronaut finds a homestead with a well. The water clears his mind, but he is powerfully drawn to the scent of a fertile woman sleeping inside. He resists the compulsion to enter, knowing he would rape and kill her. After this internal struggle, two large dogs attack him. Back in the present, Eli drives the Maslins to an isolated mountain compound. He explains that the community is composed of people who were also abducted. There, Meda confronts Blake, declaring she wants him. Eli explains Meda will be his jailer. To demonstrate their superhuman abilities, Ingraham throws a knife; in a blur of motion from Eli, the knife ends up embedded in the floor at Blake’s feet. Eli then shows Blake a scar from a rattlesnake bite, claiming the snake died after biting him.

The astronaut’s past continues as Gabriel Boyd, the patriarch of the homestead, stops the dog attack. Exhausted, the astronaut faints. He awakens cleaned and clothed, realizing his rescuer is now infected with the extraterrestrial microorganism. He understands the organism’s purpose is to survive and multiply through new hosts, a compulsion he cannot fight. When a woman brings him food, he scratches her wrist, ensuring her infection. He gives a false name, Jacob Moore, to hide his identity as a member of the lost Clay's Ark crew.

After a large meal at the compound, Meda leads Blake to a locked bedroom. He attacks her with a dinner knife, but she easily overpowers him with her superior speed and strength. During the struggle, she scratches his arm and face, inoculating him with the disease. She explains it is a microbe from a planet orbiting Proxima Centauri, brought to Earth by Eli, the sole survivor of the Clay’s Ark. The organism rewrites the host’s DNA, making them no longer human. In the past, Meda Boyd recognizes the astronaut as Asa Elias Doyle, or Eli. Compelled by the organism, he touches an abrasion on her hand, infecting her. He recalls that his wife, a doctor on the Ark, discovered that hosts can only survive the disease's toxic initial stage through repeated reinfection from another carrier.

Blake examines Meda with his medical bag, which identifies microbes altering her cells. Meda explains the intense compulsion to spread the disease. Eli brings Keira to see Blake, who uses his bag’s screen to silently communicate an escape plan. Keira agrees to help him at 2:00 a.m. In the past, Eli infects the entire Boyd family. As the disease takes hold, they experience heightened senses and uncontrollable lust. Meda’s brother, Christian, becomes incestuously drawn to her and faints upon touching her. Overcome by their own compulsions, Eli and Meda have sex.

Rane is taken by Ingraham to the house he shares with his pregnant partner, Lupe, who infects Rane by scratching her cheek. They introduce her to Jacob, a beautiful but distinctly non-bipedal four-year-old. In the past, the disease kills Meda’s father, mother, two brothers, and her sister-in-law Gwyn’s premature baby. Meda survives, and she and Eli grow close. Eli realizes he must find mates for the other surviving women, Gwyn and Lorene. Rane is then introduced to Stephen Kaneshiro, a former concert violinist intended to be her partner. He explains he stays willingly to prevent a global pandemic. That night, Lupe ties Rane to a bed. Jacob visits and chews through her bonds with his sharp teeth. Hearing her family escape, Rane flees, running down a steep incline to intercept their car.

At the planned time, Blake uses his medical bag to create a sedative, which he injects into the sleeping Meda. He escapes the room using a key from around her neck. He finds Keira waiting with the car keys, which she obtained by striking Eli with a heavy bookend. They flee in the Wagoneer, pursued on foot by the unnaturally fast community members. During the escape, a rockslide blocks the road. Rane, who had been freed by Jacob, sprints down the mountain and leaps onto the fleeing vehicle. Once clear, the girls reveal that the cat-like creature that ran alongside the car was Jacob, and all children born to the infected are quadrupeds.

In the past, Eli, Meda, and Lorene abduct Andrew Zeriam, whom they rescue from a car gang. Lorene infects him, and he accompanies them back to the ranch. In the present, Eli tells Keira the full history of the organism. She meets another quadruped child, Zera, and finds her beautiful. Eli admits he has resisted infecting Keira because her leukemia makes her survival uncertain. Later, feeling ill, Keira is given her medication by Eli. She initiates physical contact, and they have sex. Afterward, remembering her duty to her father, she knocks the sleeping Eli unconscious with a bookend and escapes to join Blake. In the past, Andrew Zeriam struggles with his symptoms and, convinced he is losing his humanity, cuts his own throat.

The Maslins’ escape is cut short when they are herded into a crash and captured by a car gang led by a man named Badger. They are taken to a ranch the gang has seized and are held for ransom. Rane reveals she has already infected one of the gang members. Blake realizes Eli’s people, who are now laying siege to the house, are their only hope. Delirious from a concussion and the disease, Blake is drawn to a young gang member named Smoke. Confusing Keira with his late wife, he nearly rapes her before Rane intervenes. Blake later breaks out a small window and escapes, but is shot as he flees.

Held captive, Rane’s symptoms manifest as an intense hunger for raw meat. The organism’s compulsion drives her toward one of the gang members, and she is subsequently raped by multiple men. The disease makes her preternaturally strong, and she fights back, seizes a rifle, and attempts to escape. She is shot multiple times but the organism keeps her conscious until a gang member kills her by sawing at her throat.

In the past, Meda gives birth to Jacob. Eli is horrified by his son’s quadruped form and obsessively tries to teach him to walk upright, eventually contemplating killing him. The community’s women confront Eli, threatening to kill him if he harms the children. He theorizes they are the "sporangia" for a new dominant life form but resolves to contain the disease on the ranch.

In the present, Keira, feeling healthier than ever, is found by Jacob, who helps her escape the besieged ranch house just as Eli’s explosives demolish it. She follows her father’s blood trail and finds him fatally crushed by a private hauler. Before dying, Blake reveals he was run down by the driver and infected him in the struggle. Eli arrives as Blake dies and confirms Rane was brutally killed by the gang. Realizing the infected hauler will spread the disease across the continent, Eli sends Ingraham in pursuit, but it is too late. He gathers his community, telling them to go home and prepare for the collapse of civilization and to protect their children, who will inherit the new world.

Months later, the world descends into chaos as the pandemic spreads. Stephen Kaneshiro learns his wife and son are lost to him in Japan. He returns to Keira, who is pregnant. He tells her of the fires and riots sweeping the globe. They accept that their children, the new quadruped species, are the future and resolve to stay together to protect them.