The BBC has cast Colin Morgan, Madeleine Mantock and Christian Cooke to lead the second series of its real-time thriller "Nightsleeper", taking over from Season 1 stars Joe Cole and Ruth Madeley. The follow-up shifts the action from a night train to a Belfast-to-Liverpool passenger ferry, which becomes the target of a hacking attack, with the crew scrambling to hide the danger from passengers while an engineer and a cyber-security official try to regain control. The announcement matters as a vote of confidence in the format from the BBC, whose drama chief Lindsay Salt commissioned the new run, and as a boost for Element Pictures, which took over production after original maker Euston Films closed.

The six-part series is currently filming in Belfast with support from Northern Ireland Screen, written by Nick Leather and directed by James Kent and Chris Baugh. Morgan plays National Cyber Security Centre technical director Stephen "Bo" Bowen, Mantock plays Beth, and Cooke plays ferry engineer Johnny, joined by a large ensemble including Rupert Penry-Jones, Ian McElhinney and Sally Lindsay, alongside three returning Season 1 cast members. Season 1 sold to 176 territories, including BritBox in the US, underlining the franchise's international appeal ahead of the sequel's launch on BBC One and BBC iPlayer.