Hunter (Haley Bennett) is a newly pregnant woman, living an idyllic, stay-at-home life with her picture-perfect husband (Austin Stowell). But when she finds herself compelled to eat a small marble, she is catapulted down the path of a new obsession for consuming dangerous objects that threatens her seemingly have-it-all life. Her husband and his mother (Elizabeth Marvel) notice the change, and begin to tighten their control over Hunter, forcing her to confront the dark secret behind her strange compulsion.