Marcella season three has introduced us to a whole new version of the beloved character, as she takes on a brand new identity as Keira.


The undercover detective returned to our screens in January 2021, three years since UK viewers last saw Marcella on our television screens. The last two episodes of Marcella season three will air Tuesday 2nd March 2021 – the first at 9pm on ITV, and then the second at 10:45pm after the news.

In the eight-part season three, Marcella is back, she's blonde, she's bearing that scar, but initially she's almost unrecognisable, on an undercover mission to infiltrate a criminal family in Belfast. All eight episodes of the series will then then be available to view on the ITV Hub.

The series stars Anna Friel as a tortured police detective who suffers violent blackouts as a result of her dissociative identity disorder, but that doesn't stop her from going up against some truly twisted killers.

The third outing for Marcella is a change of pace from what we've seen before, taking a deeper dive into her complicated psyche and the devastating trauma therein. Season two concluded with a devastating cliffhanger that saw our tortured detective leave her old life behind.

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"It was intentional to kind of reinvent it," explained Marcella creator Hans Rosenfeldt. "We wanted to do something else, and see if we could reinvent the show, but still kind of make it the third chapter in a trilogy," he told Digital Spy.

In season three, Marcella is now operating in Belfast as an undercover detective, but is she enjoying being at the centre of the criminal Maguire family a little too much?

As Marcella investigates their activities, questions are raised about how much of her old self she has left behind. Will her past come back to haunt her once again?

Read on for everything we know so far about Marcella season three.

Marcella season 3 UK release date

The final two episodes of Marcella season three air Tuesday 2nd March 2021 – one in the usual slot at 9pm on ITV, and then again after the news at 10:45pm.

ITV previously confirmed the premiere date for Marcella season three: Tuesday 26 January at 9pm on ITV.

Fans across the pond didn't have to wait quite so long, as the new season premiered on Netflix internationally from Sunday 14th June 2020 (note: Friel's tweet incorrectly states 4th June, which she later acknowledged to be a typo).

It's been a long journey bringing Marcella season three into the world, as it went into production way back in March 2019 and filmed throughout the spring and summer.

Friel gave fans a peek behind the curtain via her social media channels, including this video which features her two adorable dogs accompanying her to set...

A later video saw Friel trapped in her trailer on a filming day, as Belfast is besieged by heavy rain and hailstones that effectively throw their schedule into complete disarray - as she describes in her caption, "a producer's nightmare".

Marcella season 3 trailer

Here's a better quality version of the season three trailer that Friel shared to her Twitter page...

Marcella season 3 cast: Who's returning?

Anna Friel, who won an International Emmy for her performance in the role, will return as troubled detective Marcella.

She will be joined in the Marcella cast by Hugo Speer (The Musketeers) who made a brief appearance in the final scenes of season two as Marcella’s undercover handler Frank Young. Fan favourite DI Rav Sangha (Ray Panthaki) is back as he becomes embroiled in an investigation close to Marcella's criminal family.

The new cast includes Amanda Burton (Waterloo Road) as the chilling matriarch of the Maguire family, Katherine, Aaron McCusker (Bohemian Rhapsody) as Katherine’s son Finn, Kelly Gough (The Fall) as her daughter Stacey and Martin McCann (Death & Nightingales) as Stacey’s wayward husband.

Eugene O’Hare (The Fall) will play local police officer Eddie, with Michael Colgan (X Company) as Rory Maguire, Paul Kennedy (Death & Nightingales) as Lawrence and Glen Wallace (River City) as past acquaintance Matt.

It is not yet known whether the other original cast members – including Jamie Bamber as DCI Tim Williamson, Sophia Brown as DC LeAnn Hunter and Nicholas Pinnock as Jason Backland – will reprise their roles in the third season.

Marcella season 3: What's the plot?

Presumed dead, Marcella has left her old life behind to infiltrate a criminal family in Belfast with her new identity as Keira. Though she has gone undercover to bring the Maguire crime family to justice, she begins to enjoy her new luxury lifestyle a bit too much. Clashing with the Maguire matriarch Amanda Burton's Katherine, it looks as though Keira is looking to gain full control of the family.

"That’s basically the arc of the show," Friel told "Marcella is much more preferring Keira and I’m not sure if she wants her old life back. I don’t think she thought there was anything redeeming abut herself and she has no point to live and that makes her even more fearless. And then she starts to come part of a world and starts to question her own moral compass and integrity."

Friel also says that the third series has completely new format, so viewers can watch it as standalone series, before catching up with seasons one and two.

“It’s not as complex as the other two and the structure has changed because it’s not a whodunit, it’s more about how am I going to bring down this family. It’s quite haunting,” she said.

Marcella creator Hans Rosenfeldt told Digital Spy that season three deliberately reinvents the show.

He said: "When we finished series two, kind of late, we wrote the last scene in the last episode of series two where she's more or less being recruited, just to have kind of an opening for series three, where we already then knew we would like her undercover. Because we couldn't really find a way to bring her back into being a police officer after all that happened to her in series two.

"So in series three, we can't have her being a police officer any more, at least not the way we used to see her."

He continued: "So that was very intentional. And then it was also intentional – and I kind of liked it, but it came with the idea of not having her chase another serial killer. Because I think by the time that we finished series two and aired series two, there have been quite a few of those shows – quite dark; quite broody; they're chasing a moral-less, elaborate serial killer.

"So we thought, 'Maybe let's not do that one more time. Let's do something completely different but keeping Marcella at the centre of it."

Marcella season 2 ending explained

The Marcella season two finale saw the life of the tortured detective unravel to devastating effect.


Not only did she have an almighty face-off with the child killer she had been hunting down all season, but as well as managing to save Edward, she also made a shocking discovery about her past.

The detective worked out after hypnotic therapy that, years ago, she had accidentally killed her baby Juliette by shaking her too hard. Racked with guilt, Marcella decided to sign over sole custody of her children to her ex-husband Jason.

She then went to throw herself off a building, but colleague Rav came to the rescue and coaxed her away from the edge. Marcella told him about Juliette and then, out of nowhere, attacked him with a toilet lid and handcuffed him to the edge of a cubicle, before cutting off all her hair and slicing the edge of her mouth with a pair of scissors.

The scene cut to nine days later, and the last time we saw Marcella she was wearing that famous green parka and sleeping rough under a bridge.

What disorder does Marcella have?

Marcella has dissociative identity disorder, which results in her suffering from violent black-outs. Check out our interview with a psychotherapist for more information on the condition.


Marcella will return on Tuesday, 26th January at 9pm and 10:05pm on ITV. All eight episodes of the series will then then be available to view on the ITV Hub. If you're looking for something else to watch, check out our TV Guide.