Unforgotten series 4: ITV's cold-case drama - Air date, filming locations, cast and more

The popular crime drama starring Nicola Walker and Sanjeev Bhaskar is back on our screens with new cast members and another decades-old mystery to solve.

By Katie Archer Published: 29 March 2021 - 4.42pm
ITV Nicola Walker and Sanjeev Bhaskar in Unforgotten

Fans of hit crime drama Unforgotten will be thrilled to hear that a new cold case for detectives Cassie Stuart and Sunil 'Sunny' Khan (played by Nicola Walker and Sanjeev Bhaskar) will hit our screens in 2021.

Here’s all you need to know about the forthcoming series 4 of Unforgotten.

When is Unforgotten series 4 on TV?

Unforgotten started back at 9pm on Monday, February 22, 2021.

The series finale aired on Monday, March 29. You can watch the whole series on ITV Hub and catch up with series 1-3 on BritBox.

Will there be an Unforgotten series 5?

*Warning: Spoilers ahead*

The  heartbreaking finale to series 4 left many viewers fearing that Unforgotten was leaving our screens for good, but no sooner had the tears dried than ITV announced that a fifth series is on its way in 2022. 

"ITV would like to thank Nicola Walker for playing the brilliant role of Cassie Stuart in four series of Unforgotten which has become one of the best loved and most critically acclaimed police dramas on TV," read a statement from the broadcaster.

"Nicola and writer Chris Lang decided that Cassie's story would come to an end last night, but that Unforgotten would continue, in series 5, with a new case, and a new 'Partner in Crime' for DI Sunny Khan."

Lang followed up by tweeting a message of thanks to the show's fans, accompanied by an image of Sanjeev Bhaskar. 

Who is in the cast of series 4?

Sheila Hancock ITV

Nicola Walker (Last Tango in Halifax, The Split) returns as DCI Cassie Stuart, alongside Sanjeev Bhaskar (Yesterday, Goodness Gracious Me) as DI Sunny Khan.

Other returning actors include Peter Egan (Downton Abbey), Alastair Mackenzie (Deep Water), Carolina Main (Blood), Lewis Reeves (Uncle) and Jordan Long (Prime Suspect 1973).

Also featuring in the cast will be Sheila Hancock (New Tricks), Susan Lynch (Killing Eve), Phaldut Sharma (Hanna), Liz White (Life on Mars), Andy Nyman (Wanderlust), Clare Calbraith (Baptiste), Lucy Speed (EastEnders) and Kate Williams (EastEnders, Love Thy Neighbour).

Unforgotten series 4: Meet the cast and characters

What will happen in series 4?

As ever, we’ll see some seriously creepy cold cases resurface for the new episodes.

In the series' opening episode, the team discovers a dismembered body in a scrap metal yard that appears to have been stored in a domestic freezer for 30 years.

Helped by a distinctive Millwall Football Club tattoo, they’re able to identify the victim as a young man who went missing in 1990.

Sanjeev Bhaskar and Nicola Walker ITV

While it doesn’t take long to trace the owner of the freezer, the detectives soon discover that he recently died a lonely, isolated man, and had a drink-driving conviction for the same night the victim went missing.

Intriguingly, it turns out that there were four other passengers in the car that night. Over the course of the series we meet the quartet - Ram Sidhu and his wife Anna who are expecting their first baby together in London; Liz Baildon and her fiancée Janet who live in Cambridge; Fiona Grayson, her partner Geoff and their children in the Peak District; and Dean Barton and his wife Marnie who live in Rochester with their disabled son, Jack, and his younger sibling, Casper. 

All in their late forties, their lives are looking good, until the mystery of the body comes back to haunt them and threatens to destroy everything they’ve built for themselves over the last 30 years.

Susan Lynch ITV

Meanwhile, Cassie has her own problems to deal with – she’d decided to retire from the police force, but when she discovers that she will not get her full pension without completing her 30 years’ service, she is forced to return to work.

It’s bad news for her, but good news for viewers who will be looking forward to seeing more of her partnership with Sunny.

Nicola Walker said: “When we left Cassie at the end of the last series she felt it necessary to stop, she definitely had what would have been loosely termed ‘a breakdown’ and we were left wondering if she was going to come back.

"When we meet her this series you realise she doesn’t really want to come back but she is in a terrible position that she will lose a massive amount of her pension pay out on a technicality if she doesn’t come back and complete a certain number of months to comply with her pension.

“It is awful, she is in a complete trap so she agrees to come back so she can access the full amount of her pension because her dad is getting more and more ill and she is looking at the fact that she will probably be financially responsible for her father’s care.

"So she is completely caught. Her entire career she has very dedicatedly given to the police force. She is angry and feels very betrayed and that’s how she goes into this series’ story."

Writer Chris Lang commented: “I am so excited to be bringing back the Unforgotten team for a fourth series, as Cassie and Sunny take on perhaps their most challenging case to date. Once again, we have assembled an astonishing cast.

"Unforgotten 4 will once again explore the fallout from and the investigation in to, an historic murder case, but the primary theme of this series, will be society’s relationship with the police. 

"The investigation will show the best of the police and the worst, and at a time of unprecedented cutbacks, it will ask a number of difficult questions about the police force as an institution. It will ask what do we expect them to be? It will ask if that is compatible with what they are capable of being? It will ask how much we now take for granted the fact that on a daily basis, these men and women walk towards danger. And, after decades of bruising revelations about their probity, it will ask if we can ever again truly trust them."

Unforgotten series 4 trailer

You can watch the new Unforgotten trailer below:

Watch all of Unforgotten season 4 on ITV Hub.

Seasons 1-3 of Unforgotten are available on BritBox.

Get six months of BritBox on us

You can opt in to a six-month BritBox trial on us when you take any of our broadband packages.