Pau is a sixteen year old boy, shy and introverted, who struggles to survive along his mother and Martin, his eleven year old brother, in a rent-controlled apartment. He slowly becomes resentful and unsociable, having tu suffer the constant bullying of his classmates; being madly in love with Marta, a girl who rejects him, which causes him a terrible frustration; and feeling misunderstood by his mother. Eventually rage takes him over. One morning he finds, by chance, an old flick blade. He decides to use it to try and get even with the world around him, but things soon escape his control: aided by his sting and his little brother, Pau breaks into Carlos' house -Marta's boyfriend-, triggering a spiral of violence.