The Nightsleeper story is about to embark on a very different kind of journey. Following the success of its first series, the BBC has announced a new ensemble cast for the second season of its gripping real-time thriller, with Colin Morgan, Madeleine Mantock and Christian Cooke stepping into leading roles. Filming is already underway in Belfast, with the six-part series once again written by Nick Leather, the BAFTA and RTS award-winning writer behind the original drama.

This time, however, the action is leaving the railway tracks behind. Instead of a train hurtling through the night, the new series will unfold aboard a passenger ferry travelling from Belfast to Liverpool. What begins as a routine journey soon turns into a fight for survival when the vessel becomes the target of a potentially deadly cyberattack. As the crew struggles to keep the true scale of the threat hidden from those on board, tension begins to build and the situation rapidly slips out of control.

At the centre of the unfolding crisis is Johnny, the ferry’s second engineer, who must team up with Bo, a newly appointed technical director from the National Cyber Security Centre. Together, they face the difficult task of understanding the attack and finding a way to stop it, while the danger around them continues to grow. And with the ferry far out at sea, the passengers and crew may have nowhere to turn if things go badly wrong.

Morgan, Mantock and Cooke will lead the new cast, alongside Rupert Penry-Jones, Ian McElhinney and Sally Lindsay. Their arrival gives the series a fresh identity while preserving the fast-moving, high-pressure storytelling that made Nightsleeper stand out. The new season will also reunite the production with Belfast, a city that becomes particularly significant this time around as the setting for the story and the production base.

Behind the scenes, James Kent and Chris Baugh are directing the new episodes, with Element Pictures, a Fremantle company, producing for BBC iPlayer and BBC One. Executive producer Kate Harwood has expressed her excitement about bringing the new maritime adventure to Belfast and working with the new cast, while BBC Drama director Lindsay Salt has teased another tense and gripping story from Nick Leather.

Moving the action from a train to a ferry could give Nightsleeper an entirely new sense of suspense. The characters are no longer racing through cities with the possibility of reaching the next station; instead, they are surrounded by open water, with the vessel itself becoming a confined and increasingly dangerous environment. As secrets emerge and fear spreads across the decks, every minute could make the difference between containing the threat and losing control completely.

With a new cast, a new setting and another race against time, Nightsleeper is clearly not simply repeating its first journey. It is taking the formula out to sea and turning a trip from Belfast to Liverpool into a potentially terrifying voyage from which there may be no easy escape.