British slasher horror. The film follows a notorious quartet of teenage YouTube pranksters who make prank calls to unsuspecting victims and post videos of the ensuing hilarity on the internet. However, one of their victims decides to turn the tables on the boys and comes searching for his revenge. He begins by tormenting Sam (Gregg Sulkin) and Brady (Garrett Clayton) over the phone after they're left home alone for the night, much like they did to him. At first, the boys are dismissive of his threats but it soon becomes apparent he's deadly serious about tormenting them, and has threatened to kill members of their families, and it's not long before he turns up in person to terrorise the boys in a more personal and gruesome fashion.