ITV has commissioned Nightswimming, a new thriller starring Lennie James, with filming due to begin in Portugal in spring 2027. The project reunites the broadcaster with Harry and Jack Williams, the writers behind The Missing and The Tourist, and places James at the centre of a murder mystery that stretches across a decade.
What is Nightswimming about?
James will play Matthew, a man who returns to his former home in Portugal after being convicted of murdering his wife and two teenage sons. The original crime took place at the family’s beachfront property while Matthew was out swimming in the ocean, an apparently ordinary nightly ritual that became a defining part of the case.
According to ITV’s official announcement on 5 November, the story moves between the events surrounding the killings and Matthew’s present-day efforts to understand what happened. His wife Beth and sons Alex and Simon were attacked in the family home. Years later, Matthew begins examining the relationships, testimony and decisions that contributed to his conviction.
That gives the series two connected mysteries. There is the question of who was responsible for the attacks, but also the question of why Matthew was convicted and whether people close to him played a part. ITV’s description indicates that his investigation will take him back into difficult personal relationships rather than simply following a conventional police inquiry.
Why Lennie James is taking the lead
James has established himself across British and international television, including Save Me, Mr Loverman and The Walking Dead. Nightswimming gives him a leading role built around a man whose public reputation and private memories are at odds.
In ITV’s announcement, James described the project as a grown-up thriller concerned with family, loss, betrayal, redemption and justice. He also highlighted Matthew’s contradictions, suggesting that the drama will ask audiences to examine its central character carefully rather than treating him as an uncomplicated hero.
That distinction matters. ITV has outlined the premise, but has not released full scripts or detailed episode outcomes. Viewers should not assume that every twist, motive or eventual revelation is already known. The production’s confirmed starting point is Matthew’s return and his determination to revisit the case that destroyed his family.
The writers behind The Missing and The Tourist
Harry and Jack Williams are writing and executive producing Nightswimming through Two Brothers Pictures, the company associated with The Missing, Baptiste, The Tourist, Liar and other suspense dramas. Their work often places family relationships and uncertain loyalties inside wider criminal mysteries.
The brothers said they enjoyed creating a small-town thriller with a morally complicated central character. ITV drama director Polly Hill commissioned the series and will oversee it for the broadcaster. The production team also includes executive producers Daisy Mount and Sarah Hammond, co-executive producer Cleo Hetherington and producer Georgina Lowe.
The setting is another distinctive feature. Portugal is not merely a holiday backdrop in the announced premise: Matthew’s former home, the coastline and the people he knew there are central to the unresolved events. ITV says filming will take place in Portugal, although specific locations have not yet been announced.
When will Nightswimming be released on ITV?
There is no confirmed premiere date for Nightswimming. ITV and production company Banijay have said cameras are expected to roll in spring 2027. That is a production timetable, not a promise that the programme will reach screens during 2027.
Further casting, episode count, a trailer and the eventual ITV1 or ITVX release arrangements have not been announced in the material available so far. Any social-media claims giving a specific launch night should therefore be treated cautiously until the broadcaster publishes its schedule.
Banijay Rights will handle international distribution, meaning the programme is being prepared for audiences beyond the UK, but individual overseas broadcasters and release windows have not been confirmed.
What makes this announcement worth watching?
The new commission brings together an established lead actor, writers with a strong record in mystery television and a premise that turns a seemingly straightforward conviction into a deeply personal investigation. It also marks another original ITV drama rather than a continuation of an existing franchise.
For viewers, the immediate confirmed news is the commission itself, James’s casting and the planned Portuguese shoot. The answers to Matthew’s questions, and the way the series ultimately tells its story, remain for the finished drama to reveal.
Sources: ITV Press Centre (5 November 2026); Banijay announcement (5 November 2026); UPI television report (5 November 2026).