Mare of Easttown ending explained

Tonight's final episode tied up all the loose ends and took us on a rollercoaster of revelations in the process, so if you're a bit confused as to how it all went down, read on for a full explanation of who killed Erin and Mare of Easttown's final episode.

*Warning: major spoilers ahead for Mare of Easttown*

We pick up from where we left off last week, with Mare heading to arrest Billy Ross, who is currently fishing with his brother John Ross, while Chief Carter tries to get Mare on the phone.

We finally see the photo that Erin's best friend Jess gave the police, and it shows – *drum roll* – John Ross in bed with Erin! It turns out Dylan had destroyed Erin's diaries to prevent the truth about John being DJ's father from being revealed, as his parents wanted to keep custody of DJ.

Mare catches up with the Ross brothers to find John pulling a gun on Billy. When Mare tells him to stop, John puts it to his own head, however Billy pushes the gun out of his hand and into the water and the two wrestle until Mare gets to them.

Back at the police station, John explains that it was him who'd sparked up a relationship with Erin whilst at the Ross family reunion, not Billy. They'd begun an affair while Erin was having difficulties with her father and John was struggling in his marriage to Lori, however Erin soon became pregnant and while John pressured her into aborting the baby, she chose to have it and let people assume Dylan, her boyfriend, was the father.

John reveals that Erin rang him the night of her death, after being attacked by Dylan's girlfriend and asked him to meet her, threatening to tell Lori about their relationship if he didn't. He says that he went to meet her but she had a gun, "waving it around and screaming about how [John] had ruined her life" and wanted John to pay for DJ's ear surgery.

John says he tried to wrestle the gun away from her but it went off, shooting her in the hand and she started screaming, so he shot her in the face. He adds that he dragged her body into the woods, cleaned up and drove back to Forest Lodge, where Frank's engagement party, to give himself an alibi. He then called Billy who helped him get rid of Erin's body.

When Mare asks whether Lori knew, he says that he convinced her to lie to Mare for him and that Billy was going to take the hit. John is then arrested but asks to meet a devastated Lori, asking her to look after DJ for him.

Meanwhile, Siobhan asks for Mare's advice as to whether she should go to university in California and Mare tells her she shouldn't stay in Easttown just because of them.

Shortly afterwards, Mare and Frank go to a mediation hearing for custody of Drew, but Carrie, Drew's mother, doesn't show up. She texts Mare to meet her outside, where she reveals that she doesn't feel she can look after Drew and that she's been using drugs again to deal with her exhaustion. Mare and Frank receive custody of Drew once again and Carrie takes herself to a rehab clinic.

A few days later, Mare, Helen and Siobhan go out for lunch with Frank and his fiancée Faye as they all discuss wedding plans, however Mare spots the woman John had supposedly been having an affair with once again. When she bumps into her on the way to the toilet, they begin an argument but the woman reveals that she hadn't resumed her affair with John and that she'd left it in the past.

Mare goes to Frank and Faye's wedding with Richard, however his contract ends at the university nearby and he takes a job in a different city. They agree to keep their relationship up long-distance and say goodbye. We all had our suspicions, but it turns out he wasn't secretly the murderer all along and was purely in the show to serve as Mare's romantic interest.

The next day, Mare is called to the house of Glenn Carroll – Betty Carroll's widower. He tells her that a few items from his house have been going missing, including his gun – a Colt Detective Special – the same gun that forensics thought had been used to kill Erin. He says that the gun went missing but then was returned to a locked box in the shed a few days later.

As the shed hadn't been broken into, Mare asks Glenn who else had access to the shed and he reveals: "the boy who mows my lawn – Ryan Ross". DUN DUN DUN! Lori and John's teenage son!

Mare checks Glenn's security tapes and sees Ryan go into the shed on the night of Erin's murder and heads to Ryan's school to question him, however when he sees Mare, he runs all the way home to tell his mum: "It's Mare – she knows, she's on her way here."

Mare takes Ryan in for questioning with Lori present and he reveals that he'd found out about John and Erin's affair and told his dad to end it, which he did. However, on the night of Frank's engagement party, he watched his dad have an incredibly heated phone call with someone and checked his phone to find texts for Erin, telling him where to meet her.

He tells Mare that he borrowed Glenn's gun and only wanted to scare Erin into leaving his family alone, but when he met an unsuspecting Erin in the park, she tried to wrestle the gun out of his hands and he accidentally shot her. He called his dad, who asked Billy to deal with the body (which would explain why Billy returned home covered in blood that night).

Billy then got into a fight at school, clearly struggling to keep the secret, however Lori assumed that the secret he was keeping was that his father had restarted with affair with the woman Lori had known about before. It wasn't until Mare had begun to suspect Billy was the murderer that John told Lori and they decided to let Billy take the hit.

Ryan is taken into custody and a distraught Lori tells Mare that she never wants to see her again, blaming her for half her family going to prison.

Later on, Lori takes Moira and DJ to visit Ryan at a juvenile detention centre where he's doing well. Siobhan heads off to university in California, Deacon Mark Burton begins delivering sermons again in the church and Mare and Lori eventually patch things up. In the last scene of the show, we watch as Mare musters to courage to go back into her attic, which she hasn't entered since her son Kevin died by suicide in there several years prior.

Who killed Erin?

While the gripping series finale took us on a number of twists and turns with Erin's murderer, we finally learn that it was Ryan Ross – the son of Lori and John Ross – who killed Erin.

He'd found out about his father's affair with Erin and after she got in touch with John again, Ryan met up with her, threatening her with a gun and telling her to stay away from his family, but accidentally shot her in the process.

Billy helped to move her body, which explains why he was covered in blood when he returned home.

For the latest news and expert tips on getting the best deals this year, take a look at our Black Friday 2021 and Cyber Monday 2021 guides.

Who is DJ's father?

John is in fact DJ's father. He'd started up a romantic affair with Erin during the Ross family reunion, and had actually been the one to buy her a necklace, not Billy (the necklace was purchased under the surname Ross).

Mare of Easttown season one is available to stream on NOW and Sky. Check out our TV Guide to find something to watch, or visit our Drama hub for all the latest news.