Nightsleeper

When Joe, an off-duty police officer travelling on the Glasgow to London sleeper train, realises that someone is attempting to gain control and drive it remotely, he calls Abby, the acting technical director of the National Cyber Security, for help. However, with the entire UK rail network soon under attack too, the pair realise that if they fail to get to everyone on board the Heart of Britain off in time, all their lives may be on the line.