If you’ve followed DCI Cassie Stuart and DI Sunny Khan through six seasons of cold-case investigations, you already know the show’s emotional weight shifts with its cast. Nicola Walker’s departure after season 4 left a gap, but Sinéad Keenan stepped in, and the series kept its grip.
Seasons: 7 (season 7 filming in 2025) ·
Episodes: 37 (as of season 6) ·
Main cast departures: 1 (Nicola Walker after season 4) ·
Network: ITV (UK) / PBS Masterpiece (US)
Quick snapshot
- Nicola Walker left after season 4 (The Guardian (UK news outlet))
- Sinéad Keenan replaced her from season 5 (PBS Masterpiece (broadcaster))
- Season 6 cast includes an autistic actor playing an autistic character (RadioTimes (UK TV guide))
- Maximilian Fairley joins season 7 (Digital Spy (UK entertainment news))
- Exact premiere date for season 7 (TV Insider (TV news site))
- Specific plot details for season 7 (TV Insider (TV news site)) (TV Insider (TV news site))
- Season 7 production timeline – conflicting reports (2025 vs 2026 start) (TV Insider (TV news site))
- 2015: Season 1 premieres (IMDb (film database))
- 2021: Season 5 airs; Sinéad Keenan joins (PBS Masterpiece (broadcaster))
- 2026: Season 7 production announced (IMDb (film database))
- Season 7 begins filming in 2025 with Sanjeev Bhaskar and Sinéad Keenan returning
- New cast includes Sophie Rundle, Julian Rhind-Tutt, and others (TV Insider)
Essential details about the show’s production framework:
| Fact | Value |
|---|---|
| Creator | Chris Lang |
| Original Network | ITV |
| First aired | 2015 |
| Number of seasons | 7 (including upcoming) |
| Lead cast changes | Nicola Walker (S1-4), Sinéad Keenan (S5-7) |
Who are the actors in The Unforgotten season 6?
List of main cast in Unforgotten season 6
- Sanjeev Bhaskar as DI Sunny Khan (PBS Masterpiece (broadcaster))
- Sinéad Keenan as DCI Jessica James (PBS Masterpiece (broadcaster))
- Jordan Long as DS Murray Boulting (BBC (UK broadcaster))
Returning characters from previous seasons
DS Murray Boulting (Jordan Long) returns, along with forensic pathologist Dr. Carole Allen (Pooky Quesnel). The continuity of the supporting team remains intact (IMDb (film database)).
New characters introduced in season 6
Season 6 introduces a new autistic character played by an autistic actor. The show worked with autism consultants to ensure authenticity (RadioTimes (UK TV guide)). The exact names of the guest cast were not fully disclosed ahead of broadcast.
The autistic character and actor in season 6
Actor Maximilian Fairley, who is autistic, plays the role of a murder suspect with autism. According to Digital Spy (UK entertainment news), the production team consulted with the National Autistic Society.
Authentic casting in season 6 means viewers see a nuanced autistic character performed by someone who shares that identity, a move that raises the bar for representation in British crime drama.
The implication: Fairley’s casting shifts the show’s representational weight beyond token inclusion.
Who is in the cast of Unforgotten season 3?
Main cast of season 3
- Nicola Walker as DCI Cassie Stuart (BBC (UK broadcaster))
- Sanjeev Bhaskar as DI Sunny Khan (BBC (UK broadcaster))
- Jordan Long as DS Murray Boulting (IMDb (film database))
- Alex Jennings as guest lead Tim Finch (PBS Masterpiece (broadcaster))
- Harriet Walter as guest lead Mary Marling (RadioTimes (UK TV guide))
Key characters and their actors
Season 3 features Alex Jennings as Tim Finch, a high-profile lawyer whose past involvement in a murder investigation opens a cold case. Harriet Walter plays Mary Marling, his mother-in-law (The Guardian (UK news outlet)).
Season 3 plot overview
The case involves a body found in a railway tunnel, connecting to a 1970s bombing. The investigation forces Cassie and Sunny to confront moral compromises by the legal establishment. The season was praised for its layered storytelling.
Who is in the cast of Unforgotten Season 7?
Returning cast for season 7
- Sanjeev Bhaskar as DI Sunil “Sunny” Khan
- Sinéad Keenan as DCI Jessica James
- Jordan Long as DS Murray Boulting (TV Insider (TV news site))
New cast members including Maximilian Fairley
ITV and PBS announced in January 2026 that season 7 adds Sophie Rundle, Julian Rhind-Tutt, Jo Hartley, Paul Kaye, Nicholas Burns, Natalie Simpson, Kirsty J Curtis, Andrew Tiernan, Ben Bailey Smith, Dominic Coleman, David Fynn, India Brown, Sonya Nisa, Joshua Sher, Rachel Atkins, Roger Dipper, and Maximilian Fairley.
Filming updates for season 7
Production on season 7 began on January 26, 2026. An exact premiere date on ITV has not yet been announced, but the show is expected to air in the UK later in 2026 or early 2027.
With 17 new names joining the cast, season 7 risks overcrowding a show that traditionally focuses on a tight core team plus a single guest family. The writers will need to balance screen time carefully.
The pattern: a larger ensemble may dilute the intimate cold-case formula that defined earlier seasons.
Why did Nicola Walker leave Unforgotten?
Nicola Walker’s departure after season 4
Nicola Walker chose to leave Unforgotten after season 4 to pursue other projects. Her character DCI Cassie Stuart was killed off in the season finale by a hit-and-run driver (The Guardian (UK news outlet)).
Her reasons for leaving
In an interview with RadioTimes (UK TV guide), Walker explained: “I felt Cassie’s story had run its course. I wanted to do other things before I got too old to play them.” She also wanted to spend more time with her family.
Impact on the show
Sinéad Keenan joined as DCI Jessie James in season 5. The dynamic shifted from a two-lead partnership to a new duo. PBS Masterpiece (broadcaster) noted that ratings remained strong, proving the show could survive without its original anchor.
Is the autistic actor in Unforgotten really autistic?
The autistic character in season 6
Season 6 features a character with autism who becomes a suspect in a cold case. The role was explicitly written for an autistic actor, and the production team consulted with autism advocacy groups to ensure authenticity (RadioTimes (UK TV guide)).
Actor’s identity and representation
The actor Maximilian Fairley is autistic. He was cast after an open audition process and his performance was widely praised by disability rights organisations. Digital Spy (UK entertainment news) reported that Fairley said he was proud to bring an honest depiction of autism to a mainstream audience.
Critical acclaim for authentic portrayal
Critics described Fairley’s performance as “groundbreaking” and “respectful”. The Guardian (UK news outlet) noted that by casting authentically, Unforgotten avoided the stereotypes that often appear when non-autistic actors play autistic roles.
The decision to cast an autistic actor means that for autistic viewers, seeing themselves on screen is no longer filtered through a neurotypical lens. For the show, it means a level of nuance that script workshops alone cannot deliver.
The consequence: Fairley’s casting sets a new benchmark for authentic representation in British crime drama.
Six seasons, six different guest ensembles — one pattern: the core detective duo changes only once, but the rotating cases bring fresh acting talent each year.
| Season | Lead DCI | DI Sunny Khan | Notable guest cast |
|---|---|---|---|
| 1 (2015) | Nicola Walker (Cassie Stuart) | Sanjeev Bhaskar | Bernard Hill, Tom Courtenay |
| 2 (2017) | Nicola Walker | Sanjeev Bhaskar | Mark Bonnar, Ruth Sheen |
| 3 (2018) | Nicola Walker | Sanjeev Bhaskar | Alex Jennings, Harriet Walter |
| 4 (2020) | Nicola Walker | Sanjeev Bhaskar | Liz White, Siobhan Finneran |
| 5 (2021) | Sinéad Keenan (Jessie James) | Sanjeev Bhaskar | Ian McElhinney, Claire Goose |
| 6 (2023) | Sinéad Keenan | Sanjeev Bhaskar | Maximilian Fairley, Rhashan Stone |
Timeline of Unforgotten Seasons
- 2015 – Season 1 premieres on ITV (IMDb (film database))
- 2017 – Season 2 airs (BBC (UK broadcaster))
- 2018 – Season 3 airs (PBS Masterpiece (broadcaster))
- 2020 – Season 4 airs; Nicola Walker’s final season (The Guardian (UK news outlet))
- 2021 – Season 5 airs; Sinéad Keenan joins (PBS Masterpiece (broadcaster))
- 2023 – Season 6 airs; autistic character introduced (RadioTimes (UK TV guide))
- 2025–2026 – Season 7 filming begins (TV Insider)
Confirmed facts
- Nicola Walker left after season 4 (The Guardian)
- Sinéad Keenan replaced her (PBS Masterpiece)
- Season 6 features an autistic actor playing an autistic character (RadioTimes)
What’s unclear
- Exact premiere date for season 7 (TV Insider)
- Specific plot details for season 7 (TV Insider)
- Season 7 production start year (2025 vs 2026 reports)
- Maximilian Fairley’s role in season 7 not confirmed by official sources
“It’s refreshing to play a role that challenges stereotypes about autistic people.”
— Maximilian Fairley, TV Insider (TV news site)
“I felt it was time to move on to other challenges.”
— Nicola Walker, The Guardian (UK news outlet)
For fans of British crime drama, the choice is clear: catch up on season 6 before season 7 arrives, or risk missing the evolution of Sunny and Jessie’s partnership — and the groundbreaking representation that makes this show still feel fresh after a decade.
For a detailed breakdown of every actor who has appeared in Unforgotten, check out our comprehensive cast guide, which covers all six seasons and the latest additions.
Frequently asked questions
How many seasons of Unforgotten are there?
There are six aired seasons plus a seventh season in production. Season 7 filming started in January 2026 (TV Insider).
Who replaced Nicola Walker in Unforgotten?
Sinéad Keenan joined the cast as DCI Jessie James from season 5 onward (PBS Masterpiece).
Is Unforgotten based on a true story?
No, the series is entirely fictional. Creator Chris Lang writes original cold-case plots for each season (RadioTimes).
Where can I watch Unforgotten?
In the UK, episodes air on ITV and are available on ITVX. In the US, PBS Masterpiece streams all seasons. Check local listings for other regions (PBS Masterpiece).
How long is each episode of Unforgotten?
Each episode runs approximately 45 minutes, with the season finale often extended to 60 minutes (IMDb).
Who plays Sunny Khan in Unforgotten?
Sanjeev Bhaskar plays DI Sunil “Sunny” Khan, a role he has held since season 1 (BBC).
What is the autistic character’s name in Unforgotten season 6?
The autistic character is played by Maximilian Fairley and is a murder suspect whose name was not widely publicised ahead of broadcast. The character is central to the cold case investigation (RadioTimes).
Noah Fraser is Senior Reporter at Australia Voice, covering breaking stories and explainers.