Living in an impoverished, post-war city, Mona has finally gotten her wish of leaving the orphanage, although she hasn't been adopted. Instead, she is going to join other children who have been given up by their families to live a better life at the Company.

The Company is one of the most successful businesses in the city. They have developed a procedure to extract memories from one person and implant them in another. The process is complex, but the Company assures the public that it is safe, but expensive. After having just been through a war, the demand is high to buy a happy memory to replace a sad or frightening one. But where do the happy memories come from?

Mona and the children were all chosen by the Company because of their exceptional memory. Trading a life on the streets or at an orphanage for warm food, clean beds and an education seemed like a good deal to Mona and the other students. Like her classmates, she is training to have a near perfect memory.

At the Company, Mona meets many new classmates, but makes only one true friend, an eccentric fellow student named Owen. Owen spends most of his time daydreaming and making up stories. The other children make fun of him, calling him a plomp. Little do they know of the power behind his ability to dream instead of just remembering information.

Because of her talents, Mona is identified as one of the top students. Under the guidance of her kind, young instructor, Harriet, she begins a training program to give her memories joy and wonder. Suddenly her days of lessons are replaced with trips to a garden and time with her daydreaming best friend Owen.

But when Owen's personality starts to change after he undergoes the procedure to extract a memory, Mona starts to suspect that the process isn't as safe as the Company claims. As she uncovers the frightening truth, she realizes that her life and the lives of the other students are in danger. Soon she and Harriet are in a race against time to try to figure out how to escape and save the students, but will it be too late?