You may be used to seeing them in TV dramas, but Stephen Graham and Daniel Mays are a cop double-act to be reckoned with in new comedy series Code 404.

The duo play two police detectives at the top of their game - that is until one of them is killed on the job and is brought back from the end thanks to Artificial Intelligence. Let’s just say he’s not quite the same.

Code 404 also stars Anna Maxwell Martin - who Mays helped to get on board with the show - in what can only be described as a mini-Line of Duty spoof reunion!

We reveal the cast and characters of Code 404, and where you might have seen them before.

Daniel Mays - DI John Major

Daniel Mays John Major Code 404 Sky UK

Mays plays DI John Major, who works in the SIU – the Special Investigations Unit – of the police. Alongside Stephen Graham’s character DI Roy Carver, the pair are a formidable double-act at the top of their game.

That is until Major is killed in the line of duty during a sting operation that goes horribly wrong at the start of the first episode.

Speaking during a Q&A ahead of the launch of the series, Mays explains the appeal of the character and what we can expect from Major.

“My agent phoned me and said ‘They want you to play a policeman, and you get killed in it’ and I thought ‘We’ve been there and done that and got the T-shirt’. 

“But with this, Major comes back as artificial intelligence [AI], he’s a valuable asset, so it takes a year for him to come back and as you can imagine, all hell ensues when he returns.

“All of his brilliant police instincts have somehow got lost in translation, so all the wiring has gone wrong, he’s knocking on the wrong doors, arresting the wrong people. It’s a comedy of errors.”

The Essex actor is having a busy year, because on top of Code 404, he’s also starring in White Lines - a new murder mystery coming soon to Netflix. Later this year, you’ll see him as another copper, Detective Chief Inspector Peter Jay, in ITV’s Des.

And if you're a fan of crime dramas - you'll know he played police sergeant Danny Waldron in the third series of the smash hit police procedural, Line of Duty.

More recently, you might recognise him from the Oscar-winning film 1917, the Star Wars spin-off Rogue One, TV drama Temple and Amazon's Good Omens.

Stephen Graham - DI Roy Carver

Stephen Graham Roy Carver Code 404 Sky UK

Graham plays DI Roy Carver, the other half of the cop duo in Code 404. Carver is leaving flowers at Major’s grave when Major turns up following his AI reboot. Needless to say that comes as something of a surprise for Carver!

Speaking during a Q&A ahead of the launch of Code 404, Stephen Graham explains where Carver is at the start of the series - and the love triangle that follows.

“Major gets killed straight away and then Carver is left on his own, and a year goes by and he’s been moved down the ranks, because he realises he’s not that good without Major. It’s a proper double-act. 

“During that time, he’s developed a relationship with Major’s missus. Not in a snide way, it started off in a comforting way, then things led to certain things… Two people came together who shared the love of the person who was no longer there. 

“Anyway, he comes back, and you can imagine the catastrophe that unfolds when he pops up from the dead.”

Stephen Graham is one of the UK’s finest actors, and the Liverpool-born star has had a stellar couple of years with roles in TV dramas including Save Me, White House Farm, and The Virtues.

You might also recognise him from films including The Irishman, This Is England, Snatch, Pirates of the Caribbean and Tinker Tailor Soldier Spy.

Like his co-stars, Graham has appeared in Line of Duty. He starred as John Corbett in series 5.

Anna Maxwell Martin - Kelly 

Anna Maxwell Martin Kelly Code 404 Sky UK

Speaking ahead of the launch of the series, Maxwell Martin explains where her character Kelly is at the start of Code 404 - and how she ends up in Carver’s arms.

“I play the wife of [Daniel May’s character] John Major, but obviously he’s been killed in action. So I’ve decided to move his partner and best friend [Roy Carver, played by Stephen Graham] in as my new fella. 

“Also, I’m retraining to be a psychotherapist and get my life back a bit. It becomes clear I wasn’t very happy with my marriage when John was alive, and that’s all a bit confusing for me and Stephen’s character, Roy.

“John just thinks we’ll be together as we were before, not knowing that I’ve changed and moved on. And also, he’s a bit of an idiot.”

The Yorkshire-born actress has appeared in the BBC comedy series Motherland and recent fantasy series His Dark Materials, as well as The Bletchley Circle, Good Omens, Bleak House and Poppy Shakespeare. 

She’ll be familiar with her co-stars as she’s also appeared in Line of Duty. She joined in series 5 as DCS Patricia Carmichael, who was brought in to investigate Superintendent Ted Hastings (Adrian Dunbar).

Other stars featuring in the new series include Richard Gadd, Michelle Greenidge, Steve Oram and Emily Lloyd-Saini.

All episodes of Code 404 are now streaming on Sky One with NOW TV.

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