Alice Butler is a “creative,” at PopCo, designing toys for pre-teens. During a corporate retreat she is invited to join a select group charged with inventing a new toy craze. As Alice struggles to maintain the outsider status she has cultivated since childhood, she reminisces about her grandparents, a brilliant mathematician and a cryptanalyst who taught her to factor prime numbers and decipher codes. Alice becomes involved romantically with a colleague whose ethics are more stringent than her own, and is soon reconsidering her lifestyle and her work at PopCo.

PopCo alternates between Alice's increasing disillusionment with her job and the story of her unusual upbringing, digressing to recount at length the history of a buried pirate treasure and to explain prime numbers, codes, and ciphers. These are not only the keys to finding the treasure, but to deciphering coded messages Alice receives at the retreat. Someone wants to communicate secretly with her, but the messages are meaningless, designed simply to test her decoding abilities and willingness to keep a secret.

Alice spends much of the retreat sick in bed, dosing herself with homeopathic remedies between visits from her new boyfriend. Eventually she is recruited into NoCo, a loosely organized underground movement working to break corporate dominance and defend human and animal rights, primarily by becoming vegetarian or vegan and performing their jobs badly.

Author Scarlett Thomas draws parallels between Alice's attempts to fit in as a girl and a young professional; whether she joins the pack or sets herself apart she is subject to myriad unspoken rules. Even Alice's freeing association with NoCo ironically entails a new set of rules for living and for avoiding detection. However, PopCo's prose is dense and its tone somewhat didactic. Alice's awakening to vegetarianism and rejection of corporate branding ultimately seem intended as an earnest critique of popular culture.