Death Valley ending explained: John Chapel reveals a huge secret!

Death Valley episode 6 sees a string of shocks for Janie, including one about her mum! Here's everything that happened in the final episode...

The episode opens at a class of 2010 reunion, and "Murder on the Dancefloor" is playing. Rhiannon (Remy Beasley) tells someone she's juggling aromatherapy with being a mum-influencer. The other woman, looking annoyed, says she's a nurse, not that Rhiannon bothered to ask her. Rhinannon's partner Rhys (Iestyn Arwel) sniffs that a nurse’s salary wouldn't help much in paying off their Tesla.

Dean is talking to Becky. He says he's running a garage, and Becky seems to be flirting a bit. Dean's wife, Amber (Amy Trigg), turns up and cuttingly suggests Becky drops in at her salon to get her tache sorted! Becky storms off, Dean says he's off for a fag.

At the end of the evening, Amber asks if anyone has seen Dean, and we hear a scream. Dean's dead!

It's Janie's old school. Dean is Janie's mechanic. Baxter says the victim was hit with a spanner and there are no defensive wounds. He was probably hit from behind. Janie says Amber's brother Harrison (Garyn Williams), whom they nicknamed pasty on account of his bad dandruff, has come to help.

Clarke is angry with Janie for working with John and says it's only because his boss is a John Chapel fan that she’s still got a job. Clarke says he can't trust her, and he feels let down that she wasn't solving the cases on her own.

John is at home complaining there's nothing on TV when he comes across an old episode of Caesar.

Harrison says Dean was a top bloke and gave him a job, and he says he'll kill the murderer. Amber keeps sobbing.

John and Janie bump into each other. Things are a bit awkward. John's not impressed she's not called him, and Janie hits back that she's been busy trying to save her career.

At the station, Evan reveals he called Dean yesterday morning about his cold case, the body in the drain, mentioned at the end of episode 5. The victim was a Dutch backpacker called Patrick De Jong. Evan says the post-mortem showed injuries from a car collision. He was over in the summer of 2010, and Evan has been ringing local mechanics all week to see if they had any records of cars with damage that would fit a hit-and-run.

Dean said he'd have to check the old records when he worked with his granddad at the garage. He said he'd ring Evan back, but he never did. Evan adds that Dean got in a fight last night with Rhys. Janie says she knows Rhys’s wife, Rhinannon.

Rhys admits having a fight with Dean. Janie says that weren't Rhiannon and Dean an item? Rhys says yes, but they were 13 at the time. Rhys says the fight wasn't about that, but that Dean had ripped him off on a car.

Janie is called into Clarke's office, and John's there. Clarke says they're so busy they're getting John in as a consultant. Evan comes in and asks for a selfie with Chapel, as his aunt is a big fan! John's pretty smug about his new job.

Janie notices that John has smartened himself up and thinks he has a girlfriend. She thinks it's Helena. John refuses to answer her questions. John thinks the murder is about rage and desperation. John says they need to ask the widow why she'd thrown Dean out. Janie's confused. John says Dean was going to the gym each night to shower and eating takeaways because he had nothing to cook on at the garage.

They go to talk to Amber at the salon. Amber says she threw Dean out because he was taking risks at the garage, dealing in stolen cars. Harrison turns up at the salon. Harrison says Dean went to see his nan in the morning. Amber thinks that's odd because he'd already gone to see her once this week. Harrison says he went to see his nan after getting a call from the police (that would be Evan).

Evan phones and says Harrison has been in prison for stealing cars. Janie wonders if Dean and Harrison were partners in crime and fell out. John says they need to visit the nan. Janie says the nan's home won't let them talk to her just yet, after her shock about Dean. John suggests that he go undercover as a national treasure. Janie tells him to go home and stay out of trouble. John ignores her and heads to the residential home. John meets Audrey, Dean's nan. She's obviously a John fan.

Audrey says Dean came over because he wanted to have a look at his old photo album. She has postcards from Dean from the holidays he had with Amber in Dubai. John looks at the photo album. John spots a photo of interest, and Audrey says he can take the photos as long as he brings them back.

John and Janie go for a coffee and he shows her the photo album. Janie says she remembers the events in the photos; it was A Level results day, and there was a massive party in the woods. She looks at a photo with Rhinannon, Rhys, Dean, and Amber. There's also a photo of Janie with Sian. "We gatecrashed," she says.

Janie wonders why Dean is interested in that photo. And John says because he'd seen a dead man. In the background is the dead Dutch backpacker, the body in the drain. John asks if Janie remembers anything from the day, and she reluctantly replies that she left early because she had a big argument with Sian.

Janie gets upset talking about it. Evan confirms it's the backpacker in the photo. He says he's been going through Dean's garage records, and one car was brought in for bodywork repairs in the summer of 2010. And the car was Janie’s! At that point owned by Sian. Evan looks at the photo again and says Sian's necklace was found in the drain near the body. "I found my hit-and-run driver," exclaims an excited Evan. Janie looks crushed.

Janie tells John that she knew Sian and she's not a hit-and-run killer who stuffs a body down a drain. John says it might explain why she took her own life. Janie says it doesn’t explain who killed Dean. John wonders if someone killed Dean to protect Sian's memory. Could it be her sister Rhiannon? Janie says she's too self-absorbed to do something like that. Janie angrily leaves John's house, unhappy that he's trying to connect the two cases.

Baxter is delighted that the spanner is the weapon. "Another Cluedo weapon ticked off," she smiles. “God, I’d love a lead pipe killer, that’s the really hard one.”

Janie talks to Rhiannon and says she was spotted regularly with Dean at a Thai restaurant. She insists they just talked and weren’t having an affair. Janie says Dean texted Rhiannon on the night he died, saying he needed to talk, and she replied on her way. She admits going back to the reunion to see him.

Dean said to her he'd been looking into the hit-and-run and knew who did it. Dean said it was Sian. Dean told her Sian had brought the car in in a real state after the results day. She told him she'd hit a deer and would he fix it. Rhiannon says Dean had left Amber, not the other way round.

Janie interviews Amber. She has been looking into her salon and believes it's a front for a stolen car business, and she says Amber is the ringleader. Janie says she's been laundering the money through the salon, and that’s why she can afford loads of holidays to Dubai. Dean wanted to stop, but Amber didn't, so he left.

Janie says that Amber heard about the police calling Dean, thought it was about the stolen cars, and she got Harrison to kill Dean. Amber denies murder.

John and Janie make up with a hug. And Janie calls John a friend, bless. They discuss Amber and Harrison. John says: "You can’t know where someone is all the time… cause you can. It's not them!"

Death Valley ending explained: The killer of Dean and the backpacker is revealed... and so is John's big secret

Janie gathers the suspects. Janie and John say Rhiannon snuck out the night of the reunion. Rhys was asleep, but then his phone pinged to tell him his car was on the move. Rhys saw his car heading back to the reunion and decided to get on his moped to drive to the reunion so he could confront Dean. Rhys saw Dean and Rhiannon together and assumed they were having an affair.

Janie produces Rhys's shoes, which she says has traces of Dean’s blood on them. Rhys admits to murder. But Janie says something's not right. John tells her to close her eyes and focus!

Janie says what actually happened was that Rhys saw Rhiannon strike Dean with the spanner because he knew the truth about the hit-and-run. It wasn't Sian after all. Sian was drunk that day and called her big sister for help. Rhiannon was the one who drove the car and hit the backpacker. She took the car to Dean to repair the car and that’s why she killed him. As for the blood on the shoes, Janie says Rhiannon chucked them on and has the same size feet as Rhys. Janie arrests Rhiannon.

Back at the station, Janie tells Clarke that Rhiannon has confessed. Clarke is grumpy that John has helped them solve another case. Janie says his guidance has been crucial, and she talks Clarke around. Clarke gets all emotional and tells Janie he's put her in for a promotion.

Janie is at her mum's. John arrives at the door and congratulates Janie on her promotion. Janie said she would invite him in, but she's off out soon with Baxter. John says actually there’s something he and her mum want to talk to her about. They're dating!!! Janie starts fuming, and they all start shouting at each other.