"The Mimic" tells the story of a young girl named Chloé (played by Sophie Nélisse), who suffers from a rare sleep disorder that prevents her from sleeping. Desperate for a cure, her mother seeks the help of a mysterious scientist, Dr. Gates (played by Jason Schwartzman). However, their solution comes in the form of a strange, chimeric creature known as "The Mimic," which is designed to induce sleep in Chloé. As the creature begins to inhabit Chloé's life, she starts to experience terrifying and unexplained events.