Hal and Bill are two twins who, in their youth, find an old toy monkey in the attic of their house that belonged to their father. From that discovery, mysterious and bloody deaths begin to occur around their circle. Seeing what was happening, the brothers agree to get rid of the terrible toy so they can continue with their lives, forgetting about it as the years go by.

When they are adults, the intriguing deaths start happening again, causing the brothers Hal and Bill to reunite to put an end to the monkey once and for all, so they do not have to mourn the deaths of those close to them, who are increasingly closer to the monkey. A bloody horror film based on the eponymous novel by Stephen King and directed by Osgood Perkins ('Longless').

Perkins has also adapted the script and stars Theo James as the lead. The actor known for his role in the 'Divergent' saga plays both twins. He is joined in the cast by other names such as Elijah Wood, famous for his work in the 'The Lord of the Rings' trilogy, and Sarah Levy, the Canadian actress we have seen in 'SurrealEstate', who plays Aunt Ida, who took care of the twins in their childhood. Additionally, the film is produced by James Wan, the well-known director of major horror films like the 'Insidious' saga and 'The Conjuring'.