Set on a sleeper train traveling from Glasgow to London, a government agency desperately tries to intervene in the rapidly-escalating events onboard. Can two people who've never met, one on the train and one not, work together to save the lives of its disparate group of passengers as the Heart of Britain service hurtles towards what might quite literally be its final destination?
The story of Gabe, an ordinary man who works as an emergency call handler for the Scottish Ambulance Service in Glasgow. His world is turned upside down when he receives a desperate life-and-death call from a woman who appears to know him. With Gabe under pressure to work out who she is, he makes a decision that threatens to have devastating consequences.