What could be more innocent than going on holiday?As a family drive along a quiet country lane on their way to the airport, they meet a stranger standing alone in the middle of the road.Steering them along another path, he tells the driver, Ben, that a tree has fallen and there's no way through.But as they make their way along the diverted route, they come across a coach blocking the road.Getting out of the car Ben goes to investigate and is horrified to find the passengers tied to their seats.Then a discarded phone starts to ring…If Ben calls the police, everyone on board will die.The caller is about to start the horrific game...