The Warning is a 2018 Spanish thriller film directed by Daniel Calparsoro and based on the novel of the same name by Paul Pen. The screenplay was adapted by Jorge Guerricaechevarría and Chris Sparling. It was produced by Morena Films.


In April 2018, 9-year-old Nico is tormented by bullies who force him to steal an X-rated magazine from a 24-hour convenience store and tell him about a man who was shot and killed there 10 years earlier. Nico is caught shoplifting by the owner, Héctor, who realizes the magazine is not for such a young boy. Héctor does not tell Nico's mother and Nico instead buys a video game magazine. Later, Nico discovers a note inside the magazine saying he must not go to the store on his birthday, April 12, or else he will be killed. His mother reports her suspicions about the bullies having written the note to Nico's school principal which then results in further retaliation.