Grace series 5 delivers some major changes for the cast and characters that play out across four new episodes.

The Brighton-based cop show, starring John Simm as Detective Superintendent Roy Grace, has become renowned for its dark plots and grisly murders, and theres plenty more of both on the way in the new series.

The new cases involve a kidnapping, a bomb threat to a football stadium, identity theft, the murder of a mental health guru and a drugs baron trying to nobble a jury.

In series 5, Grace is put through the wringer, professionally and personally, like never before.

Read more: Doctor Who and Star Wars actors guest star in Grace series 5 episode 1

What happens in Grace series 5

This series marks some significant alterations to the shows format, with a new member joining the regular cast, another popular cast member going AWOL, and a shift in the central ongoing mystery.

This used to be the show about "the cop whose wife went missing". But that was cleared up last year, leaving Grace free to marry his pregnant pathologist girlfriend, Cleo.

Or so we thought.

The new series starts with a heartbreaking revelation about Grace and Cleos private life – theyve lost their unborn child.

Grace and Cleo lose one child – and gain his son Bruno

Things are further complicated with the introduction of Bruno – the son Grace never knew he had – into his life. With his ex-wife, Sandy, apparently having died (but as they always say about crime shows, never believe it unless youve seen the body), Bruno is being looked after by Sandys parents, with Grace helping out when he can fit in his son in between cases.

Its a very complicated and strange situation for Grace, because he is also dealing with his son Bruno turning up as well and hes trying to get to know him, says John Simm. Its even stranger for Cleo, because suddenly there is a kid in her life who isnt hers. Theres a moment where Bruno asks Cleo if she is a mummy and its just so raw for her. Then Grace and Cleo start to think about whether or not they want to try again, which is such a big decision.

Cleo was quite far along in the pregnancy as well, adds Zo Tapper who plays Cleo. So it was not expected at all. We dont delve enormously into exactly what happened and the complications of that, but we certainly see the aftermath and the deep, profound sense of loss and shock that they face.

John, renowned star of Life On Mars, seems to think the show wouldnt be the same if Roy were ever allowed to be completely happy: Youve got to have some kind of conflict otherwise its all too happy – nobody is interested in watching a detective who is happily married and happily solving cases because hes really good at it. Something needs to happen for the drama to work.

New mystery for series 5 now Graces missing wife puzzle has been cleared up… kind of

At the end of series 4, Grace discovered that his wife Sandy, who had been missing for a decade, had taken her own life not long after the former couple had shared a painful reunion.

It was at this point Grace had also discovered he had a son. This series has a lot of unanswered questions to address.

I was worried about the Sandy storyline being tied up at the end of last series, because that was his thing – hes the detective with the missing wife, admits John.

I was worrying where the conflict would be, but trust me, theres loads more to come. Nothing is ever tied up – just when you think its all done its not, theres plenty more in store.

Sandys death left some plot threads dangling. Specifically, that she had a relationship with Graces boss, Cassian Pewe – which Grace still doesnt know about – and that Cassian saw Sandy when she briefly returned to Brighton, which for some reason he has not yet told Grace about.

Changes to main cast of Grace for series 5

The vast majority of the cast is returning including John Simm as DS Roy Grace, Richie Campbell as his best bud and work partner DI Glenn Branson and Zo Tapper as Graces fiance and Senior Anatomical Pathology Technician at Brightons mortuary, Cleo Morey.

Well also be seeing more of Brad Morrison as Sots cop DC Nick Nicholl, Laura Elphinstone as the North Easts finest export DC Bella Moy, Carolina Valds as chief pathologist Nadiuska De Sancha and Sam Hoare as Graces posh, snide boss ACC Cassian Pewe.

Youll find out a lot more about Nick and Bella this series, says Richie Campbell. So everyone gets a moment.

Outside of the police force, Rebecca Scroggs is back as Glenns wife, nurse Ari Branson, wholl be having a major, ongoing malpractice storyline of her own in this run.

But there is one member of the original cast we wont be seeing around…

Has Craig Parkinson aka Norman Potting left the show?

Yes, Craig Parkinson, who played the much-loved, unapologetically un-PC cop Norman Potting, is no longer in the show. He announced his departure on Instagram last year when series 4 began airing.

Its been a wonderful experience taking this character from page to screen & updating him for a new audience, he said. There was a huge sense of responsibility in portraying such a character from @peterjamesuk much-loved book series but with a few tweaks here and there from our excellent script team and the support from Peter, Im really glad that he resonated with the audience.

Normans departure from Grace is acknowledged but not fully explained in the opening episode of the series 5.

When we last saw him, he was in a fairly new relationship with Bella, but also reeling from a prostate cancer diagnosis. Its very much in Normans character to simply walk away and deal with something like that on his own.

New Grace cast member for series 5

There is a replacement for Norman, but not straight away. And shes definitely not a like-for-like replacement. After all, you wouldnt want to replace Norman with a character whos just Norman-but-not-as-good.

We first meet headstrong DC Vee Wilde, played by Juliette Motamed, in episode 2, and though Grace tells the team she comes highly recommended, she doesnt make a good first impression on Bella, and clearly has a lot to learn.

Will those villains who got away last series – Alvin Smallbone and Dr Crisp – be returning?

Grace is often in contention with his bosses for not tidying up cases with a neat bow. There are at least two villains from last series who are still at large, who both hinted they would be back: small-time gangster-with-a-grudge Alvin Smallbone and serial killer Dr Crisp, who somehow survived being buried under falling rubble.

Crisp actually turned up again in the book that the final episode of series four was based on, Love You Dead though was absent from the TV adaptation. So will he emerge in one of series 5s episodes instead?

Neither of the actors who played Alvin Smallbone (Niall Greig Fulton) and Dr Crisp (Keir Charles) are listed in the series 5 press pack, but the production team may be just trying to avoid spoilers.

And while not a villain, it also seems the journalist character Siobhan Sheldrake (played by Jan Le) has been quietly dropped (she was the nice one, trying to foster positive links between the press and police, rather than the scummy one who was bugging Graces car).

What are the stories for this series?

The four episodes for Grace series five are:

Dead If You Dont: A bomb threat at a football stadium on match day leads to the botched kidnapping of one of the football clubs wealthy shareholders.

Dead At First Sight: A businessman having a secret liaison with his mistress in a Brighton Hotel is found dead but it looks like a whole string of women (and a man) were trying to get to meet him. And most of them seem to have no connection to him.

Need You Dead: The murder of a former psychiatrist and creator of a popular mental health app triggers a case that leaves Grace doubting his own abilities, and the East Sussex CID in tatters.

Find Them Dead: Grace tries to prove that somebody is attempting to fix the trial of a notorious drug baron, while his team investigate a double murder in a park. Grace also learns something that leaves him reeling.

According to John Simm: Series 5 ends on a bit of a cliffhanger. Theres a huge storyline that we will pick up in series 6 and the stakes get higher every season.

Are the stories in series 5 the same as the ones in the Peter James books?

The TV episodes roughly follow the plots of the books but, says John Simm, theyre doing their own thing more and more as the show evolves.

Weve started to veer away from the books. Bella dies early on in the novels and we didnt want her to, so shes very much alive in our series. Theres another big change this series, in that Norman Potting is no longer there, but hes in the books," he explains.

"Also, many of the books were written a long time ago, so they do need bringing up to date. That means Im not worried about people thinking they know whats going to happen next, because the rug will be pulled from under them!

That sounds like a hint to us!

Big name guest stars for Grace series 5

Faces you might know among the guest stars of series five include:

Shaun Dooley, who appears as Terence Maxwell in episode 4, will surely be familiar to all viewers, thanks to his impressive TV CV that includes roles in Its A Sin, Gentleman Jack, Mr Bates Versus The Post Office and the Alan Carr sitcom Changing Ends (as Alans dad Graham).

Georgina Rich, playing jury member Meg Magellan in episode 4, stars as Charlies mum in the Netflix hit Heartstopper.

Holli Dempsey, who is phishing victim Sam Fordwater in episode 2, is well-known from the Ricky Gervais comedy Derek and the first series of Harlots.

Shaun Dingwall, who plays Joseph Ludlow in episode 1, is best remembered for playing Roses dad in various early episodes of the Doctor Who revival. He also played Jeffrey in series 3, 4 and 5 of Top Boy on Netflix.

Abhin Galeya, who appears in episode 1 as football club shareholder Kipp Kavinda, has recently appeared in five episodes of the Star Wars spin-off Andor.

Gethin Anthony, who plays Marcus OSullivan in episode 3, is probably best known as Renly Baratheon in Game Of Thrones.

Release date

Grace series 5 premieres on Sunday, April 6 at 8pm on ITV1, with the next three feature-length episodes on subsequent Sundays.

All four new episodes are now available on ITVX.

Seasons 1 – 4 are also available to stream on ITVX.