Oryx & Crake follows the viewpoint of Snowman/Jimmy, who believes he is the “Last Man” to survive an apocalyptic plague. The story is comprised of two timelines: the aftermath of the plague and flashbacks to Jimmy’s life, from childhood and all the way up to his present circumstances.
The novel starts off with Snowman sitting by the beach, continuing with his daily routine, which consists of gathering food and talking with the Crakers. Snowman sees himself as the Crakers’ caregiver, telling them stories about their creators, Oryx and Crake; in the process of his daily storytelling, he provides the Crakers with an origin myth while revisiting his own past.
Through the flashbacks from his past, we learn how Jimmy grew up in one of the wealthy compounds, gated communities run by corporations. Jimmy’s father and mother work for the corporation but Jimmy’s mother is appalled by their corruption and experiments on animals. She quits her job and leaves Jimmy and his father behind. Later on, we learn about Jimmy’s adolescent friendship with Crake, who is extremely gifted with scientific intelligence. Together the two play violent online games and watch pornographic videos. An important game they play is Extinctathon, a cataloguing list of extinct species, which foreshadows the two boys’ future role in the apocalypse. Another key moment in Jimmy’s youth is when watching child pornography, he notices a young girl in a video, and when he meets Oryx years later, he is convinced Oryx is the same girl.
Jimmy and Crake eventually go to different colleges. Crake goes to a gifted school for students with science intelligences while Jimmy goes to a school of humanities. He graduates and lands a job writing pamphlets for a corporation called AnooYoo. During this time in his life Jimmy is depressed and unfulfilled; he develops habits of alcohol and sex addiction. He sees Oryx on television again, involved in a sex-trafficking scandal. Jimmy also learns that his mother has been executed for treason. Crake and Jimmy resume their friendship when Crake offers Jimmy a new job at RejoovenEsense, where Crake is leading a secret science project.
In the present, Snowman tells the Crakers that he must leave for a while in search of food and weapons. The Crakers insist on going with Snowman but he tells them he must go alone. Snowman cuts his foot on glass where he must treat a growing infection. During this travel, we get flashbacks from Jimmy’s time at the RejoovenEsense compound and his involvement with Crake’s project. Crake’s project is a two-part plan to eliminate human suffering. The first pill of the process is BlyssPluss, which essentially sterilizes humans to reduce over-population. The second part involves human embryo manipulation, genetically creating the Crakers.
Jimmy sees Crake’s employees, one of whom happens to be Oryx and she is the caretaker of the Crakers, teaching them to eat and survive. Crake and Oryx have a sexual relationship; however, Oryx has become deeply involved with the Crakers and tells Jimmy he must promise to take care of them if anything ever happens to her. One day Oryx calls Jimmy to let him know the pill she had been distributing has manufactured the plague.
Jimmy waits for the plague to be over, and Crake eventually returns to the compound; with Oryx slung over his shoulder, he looks at Jimmy, tells him to take care of the Crakers, and proceeds to slit Oryx’s throat. In complete disbelief, Jimmy shoots Crake.
After his journey back to the “Egg,” Snowman returns to the Crakers, who are overjoyed to see him. He learns from the Crakers that they have noticed other men are nearby on the beach. Interested and wary, Jimmy travels along the shore with his gun, unaware of what could happen next, or what he might have to do to keep his promise to protect the Crakers…