Actor Lennie James (The Walking Dead, Save Me) is playing the lead role on ITV Thriller Nightswimming. According to Deadline, the creators of Nightswimming, Harry and Jack Williams (Fleabag, The Tourist), will have James will play Matthew, whose return home will be the start of the series.

Nightswimming is set in past and present events about a man, Matthew, accused of brutally murdering his wife and two sons years ago. In memories, Matthew goes back to that night with him swimming in the ocean while his family was attacked in their beach home. In the present, Matthew investigates the crime, confronting old friends and interrogating people who’ve built the case against him. The series continues with the investigation in Portugal where Matthew lives.

The Williams’ brothers had worked from their Banijay-backed indie Two Brothers Pictures for Fleabag (2016-2019), The Tourist (2022), and Prime Video’s upcoming series Danger Money, with Ray Winstone (The Gentlemen, Damsel) starring in it.

James is mostly known for his role in The Walking Dead (2010-2022) as Morgan Jones and was on for several seasons. Nightswimming is one of James’ big roles after winning a BAFTA for BBC’s acclaimed adaptation of Bernardine Evaristo’s Mr. Loverman (2024). He has also appeared Mayor of Kingstown (2021- ), Save Me (2018-2020), and Line of Duty (2012-2021). He previously was on ITV show called The Prisoner (2009) with Ian McKellen (The Lord of the Rings, X-Men) and Ruth Wilson (The Affair, Luther).

James said: “I am very excited about getting going on Nightswimming. It’s a juicy, grownup thriller about family, love, loss, betrayal, redemption and the price of justice. Matthew is the kind of character I love to play full of complexity, contradiction and conviction This is top notch storytelling, and I’m chuffed to be a part of it.”

The Williams Brothers added: “We absolutely relished writing Nightswimming, it’s a small-town thriller with a morally murky edge, grounded in a knotty, complex character. We can’t wait to work with ITV again and to see what Lennie – who are thrilled to have on board – does with Matthew when we begin filming in Portugal next year.”

The Williams work with executive producers Daisy Mount (Wilderness, The Rig), Sarah Hammond (The Tourist, Dinosaur) and James, co-executive producer Cleo Hetherington (Doctor Foster: A Woman Scorned, Do Not Disturb), producer Georgina Lowe (Malice, Black Mirror), casting director Kelly Valentine-Hendry (Rivals, Bridgerton).