400 miles in less than four hours from Glasgow to London: The Night Sleeper actually promises a relaxed overnight ride. But when the train leaves the Scottish metropolis, no one suspects that this is the start of a dramatic journey. On board, Joe, a policeman who is not on duty, notices that someone from the outside is trying to take control of the train. He calls Abby, a cyber expert in London, for help. It quickly becomes clear to both of them that the train has been hacked and the entire British railway network has been attacked... A night train races from Glasgow to London - as if controlled by magic and no one can stop it! The BBC series skilfully creates the highly dramatic thriller scenario of "hackjacking" - a train hijacking by a terrorist cyber attack. The real-time thriller series captivates with a mixture of fast-paced action adventure, classic mystery and an exciting crime story in the spirit of Agatha Christie - in which no one is quite who they seem to be.