Shetland season 9 ending explained: who killed Annie and Bergen?

Shetland season 9 sees Ashley Jensen return as DI Ruth Calder as she is once again thrown into a dark and distressing case that she fights to solve with her colleague and friend Tosh (Alison O’Donnell). This season sees the pair drawn into a deeply personal investigation for Tosh when her friend, Annie Bett is murdered and soon the pair are drawn into a web of lies and deception.

Here is everything that happened in the last episode of Shetland season 9...

The final episode of season 9 opens with a flashback to the night Annie was killed, and Noah and Annie are sitting in the car, waiting for Bergen at the research facility. Noah is reeling off prime numbers to his mum while they wait, and soon an upset Bergan gets in the car and tells Annie that Stefan knows they are trying to help Astrid and he's cross. Annie tries to calm him down and says she knows somewhere they can hide out until Stefan calms down, meaning the old house they are eventually killed in.

In the present day, Tosh and Calder are interviewing Kyle Frost about the shooting in Manchester and his connection to Lisa Friel. He admits they were a couple but she was too much so he ended things. Tosh and Calder go and question Lisa at Alan's house while uniformed police search her campervan. She admits to knowing Kyle and that they dated, but says that she doesn't know about Annie's murder and that they argued over Annie finding drugs in her room.

As Sandy tells Calder that Kyle's alibi for the night Annie was killed checks out, she and Tosh go to the help centre called Hem where Annie volunteered and where Lisa was staying before moving into Angus's campervan. They ask the lady who runs it about the argument between Annie and Lisa and she doesn't know what it was about but she does know Annie was upset.

Michael, Ian's brother-in-law turns up at Hem and Tosh and Calder ask him about Lisa, and he comments on how close she is with Alan, Calder's brother. At the same time, Lisa is packing her things to leave, despite the police telling her not to go anywhere. Alan tries to stop her and she hits him, leaving a big cut on his face.

Alan calls Calder and says Lisa needs to talk to her, and that she needs to listen. At the church, Lisa admits it wasn't an argument between her and Annie, but that Annie was trying to help her, but she won't say why.

Lisa admits to having Kyle's gun, saying that he'd asked her back in Manchester to get rid of it, but she had kept it. She says that when Annie left Hem that night, she took Kyle's gun with her becasue she was worried that Lisa was going to use it after what happened.

Calder is cross that Lisa still won't say more, but Tosh takes a gentler approach and realises that someone did something to Lisa, she had confided in Annie and the 'argument' was becasue Annie wanted her to report the incident to the police.

Lisa reveals that she was sexually assaulted and when Calder and Tosh get in the car, Calder tells Tosh that she has read her file and that if she ever needs to talk, then she is there for her. Tosh assures her she is okay but is grateful, and they head off to find their mystery attacker - who turns out to be Annie's brother-in-law, Michael.

Noreen is at Ian's house to see how Noah is getting on and they talk about his reoccurring nightmares while her husband, Michael, is being questioned by the police.

Tosh and Calder talk through the assault on Lisa with Harry, telling him that it happened the month before and that the only person she told was Annie, making Annie a threat and giving Michael a motive for killing her. The fact that Annie had the gun on her also changes the nature of the killings, as the suspect must have got their hands on the weapon at the croft, meaning it is no longer premeditated.

Michael denies attacking Lisa and says you can't believe a thing she says and that although he was at Hem that night, he didn't see Lisa and went for a drink with his friend Frank after his meeting. Calder and Tosh clearly don't believe anything Michael is saying and think that what Annie wanted to speak to Tosh about before she died was probably about Lisa and the attack.

Tosh and Calder go over what could have played out at the croft the night Annie and Bergen were killed, but something still doesn't add up with what they now know about the gun and Michael. So Tosh goes to see Michael's friend Frank to confirm that he went for a drink the night of Lisa's attack as Michael claims.

Meanwhile, Noreen and Ian have taken Noah to a coffee shop to get him out of the house, but he wanders off and has a panic attack. Ian finds him and manages to calm him down.

Elsewhere, Tosh questions Frank about his night out with Michael and he confirms that he was at the pub but afterwards Michael didn't want to wake up Noreen and Finn and so went back to Hem and planned to stay the night. At the station, Sandy and Billy look over Michael's statement taken the morning after the murders and he says he was at his office at the council building until 2am. While there is no one to confirm this as no one else was working that late, Sandy finds out that Michael called Noreen around 10pm the night of the murders and that his debit card was used to pay for some petrol a mile from where Annie was at the party. Sandy calls the garage to get some CCTV so they can place Michael near Annie on the night of the killings.

Tosh and Calder interview Michael again and he finally admits to being at Hem the night Lisa was assaulted but maintains that he didn't kill Annie and Bergen. As Tosh and Calder push him to say more, he finally shouts that it wasn't rape before clamming up again, clearly regretting saying too much.

Meanwhile, Ian makes Noreen drive to the croft with Noah and makes his son go inside despite Noreen protesting that she doesn't think it is a good idea. Ian tries to help Noah's nightmares by showing him it is just an old house and there is nothing there that can harm him, but when Noah runs out Ian is at a loss and starts smashing the house up.

Back at the station, Tosh and Calder are trying to find a way to prove that Michael is the one who killed Annie and Bergen when Billy comes in and says Noreen has called and is concerned about Noah after Ian took him to the croft. Calder races to the old house and finds Ian trying to break the house down. She calms him as he breaks down and sobs. Outside a storm has come and Noreen puts her green coat on and as the rain falls on the fabric, Noah seems to be remembering something. Could this be a link to the lizard he keeps seeing in his nightmares?

At the station Sandy shows Tosh the CCTV from the garage the night that Annie was killed and it isn't Michael on the video, it is Noreen. Tosh calls Calder, who is still at the croft, and tells her that Noreen must have used Michael's card and the reality that Noreen killed Annie and Bergen hits.

Calder tells Tosh to get a unit to the house immediately, while she goes to find Noah, who is now terrified of Noreen, having realised that she is what is chasing him in his nightmares. Calder tells him calmly to get his dad and wait in her car... but when he seems too scared to move, she whispers to him that 'she knows' and he understands what she means and runs to get his dad.

Noreen realises that Calder has worked out that she is the killer and tries to get in the car to escape, but Calder gets in the passenger seat and takes the car keys from her. Calder asks Noreen if she saw Annie that day she died and at first Noreen is reluctant to talk, but when she realises there is no way out, she confesses that Annie dropped in on her way home from seeing Lisa on the day she died and told her there had been an accusation against Michael and that she thought she should know as it was serious.

In a flashback, we return to the night of the party, just before Annie was killed. Noreen tells Calder in a voiceover what happened, explaining she went to find her at the party to convince Annie not to go to the police, but then she saw her talking to Tosh. She thought it was too late, so she followed her to the marine research facility where she got Bergen and then Noreen followed them to the croft. In the flashback we see Annie taking Bergen into the croft with Noah and getting Noah settled to sleep in the bath, but the whole time she has the gun on her from Lisa as protection in case Stefan comes to find them. Meanwhile, Noah sees someone watching the house from afar, but he doesn't register it is Noreen.

In the house, Annie puts the gun on the side and calls Euan Rossi askign for help but is shocked when she turns around and Noreen is standing behind her. Annie tells Noreen to go home and promises she hasn't said anything to Tosh, but that doesn't mean she won't.

Noreen sees the gun on the side and picks it up, but as Annie tries to get it off her, it goes off and Annie is shot. But before Noreen can register what has happened Bergen appears at the door to see what is going on and she shoots him, however, he isn't quite dead, so she shoots again, and this is the gunshot that wakes up Noah. Stunned by what has happened, Noreen runs away.

In the present day, Noreen is telling Calder that she threw the gun in the sea and Calder is sickened that Noreen left Noah in the house to find his mum's dead body. Noreen breaks down in tears and says she was trying to protect her family. Soon Tosh arrives with uniformed officers and arrests Norrenm while Ian and Noah get out of the car and the reality that his sister killed his wife hits Ian.

Later, at Alan's house, Calder tells Lisa that Noreen has been charged with the murder of Annie and Bergen and the police have submitted the evidence against Michael and they should hear back soon. Lisa is worried about what will happen to Noreen and Michael's baby if both his parents are in prison, but Calder tells her not to worry about that and that she deserves justice for what happened.

Angus is outside waiting for Lisa so they can head off on another of his conspiracy theory investigations. Once they are gone, Calder emerges from the house with a case of Alan's dinosaurs. She wants to give them to Noah, but he isn't sure as he is clearly fond of them despite being grown up.

Calder invites Alan to hers for dinner the following night, which is big progress for the siblings considering at the start of last season they weren't even talking. Calder goes to see Ian and Noah and Ian tells her that they're moving to Edinburgh. He also reveals that he got a letter from Rossi about Annie's past as a spy and that he is going to keep it to give to Noah when he is older. While Ian is on the phone with the estate agents, Calder gives Noah the dinosaurs and they have a quiet chat and she seems to have got over her fear of children!

At the end of the episode, Tosh goes to a bar and sees her friends there having a drink. They ask her to join them, but she turns them down awkwardly and finds a seat. Soon Calder joins her and they order a bottle of wine and laugh together, their relationship officially moving on from colleagues to friends.

All episodes of Shetland season 9 are now BBC iPlayer.