Nightsleeper is a thriller in which a train is ‘hackjacked' while travelling from Glasgow to London, and suddenly finds itself on an uncertain journey with an even less certain destination. Part fast-moving heart-in-the-mouth action-adventure and part twisty-turny whodunnit detective story, it's a roller coaster ride set across a single night where no-one is ever quite who they seem. 

Leading the fight are Joe Roag, an off-duty police officer who is a passenger on the train, and Abby Aysgarth, the acting technical director at the National Cyber Security Centre (NCSC). To stop the train, they'll have to work out exactly who's behind this. But are they fighting a hostile state, a terrorist organisation, or organised crime? Who is the self-styled ‘Driver' who seems to be one step ahead of their every solution?

As Abby and Joe - who have never met in person - try to establish a bond that will withstand everything the night throws at them, will Joe's fellow passengers help or hinder their desperate efforts? Could one of them even be involved? Who can Abby and Joe really trust?