Shetland on BBC One: 6 shocking revelations in episode 4 including the possible corruption of Sgt Billy McCabe
Oh Billy, you'd better have a bloody good reason for this!
Shetland series 10 has delivered quite the curveball this year, throwing the shadow of doubt on fan favourite Sgt Billy McCabe – and episode 4 hammered another nail in his coffin.
In this week’s episode (Wednesday, November 26, 2025), a desperate Stevie battled to keep her sister Amy close, but it wasn’t easy. Especially after Amy discovered some damning news about her troubled sister.
Meanwhile, DI Ruth Calder set her informant Louden a very dangerous task – with violent consequences – and Tosh and Sandy dug into Robert Tulloch’s career in the police.
That’s where the most shocking twist came at the end of the episode when their investigation threw Billy’s previously impeccable reputation into the mud, too.
Here’s a recap of what happened in Shetland series 10 episode 4.
***Warning: spoilers from Shetland series 10 episode 4 ahead***
Shetland series 10 episode 4: Is Will Louden dead?
DI Ruth Calder was on a mission to bring down the drug-dealing Callaghan family this week. In a bid to find out the identity of the Callaghans’ contact in Shetland, she piled the pressure on Will Louden to dig into the family and put him in grave danger.
He reluctantly agreed… Although, to be fair, he didn’t have a lot of choice as Calder emotionally blackmailed him with the promise to help him see his estranged child. Her harsh tactics were all in a good cause, but they put Will’s life at risk.
He warned her “it was too dangerous”, and he was right. When he started asking questions, Callaghan’s henchman Mitchell started followed him. It wasn’t long before he saw Louden meet up with DI Calder, and knew he’d found the “grass”.
At the end of the episode, Calder found Louden slumped unconscious by a wall. Although it wasn’t clear if he was dead, it had been made to look like he’d taken an overdose.
Perhaps if Ruth Calder had been a bit more careful with her informant, then he wouldn’t have been left fighting for his life.
Stevie Shannon’s real motives revealed and why she attacked Morag
In Shetland series 10 episode 4, the focus was very much on Stevie Shannon. We discovered – as if we hadn’t already guessed – that she had made the call to social services about her sister. Wow, what an absolutely cow.
Understandably, Amy was devastated to find out her sister was behind it. We learnt that Stevie just wanted Amy all to herself, and resented her life with her husband Luke and son Aiden.
A clearly very unwell Stevie believed that the whole world was trying to “get between her and Amy”, including Luke and Aiden. Of course, because she’d made a malicious report, the police were able to arrest her. Crucially this gave them reason to take her fingerprints. Viewers will know that there was a third set of prints found in Eadie Tulloch’s house.
Of course, when social services had been called it was Billy’s wife Morag who attended the scene. We know she was involved in Stevie and Amy’s case back in the day, alongside Eadie Tulloch.
Trying to defend herself to Amy, Stevie told her: “I’m going to put things right. I’m going to make sure she can’t take Aiden off you.”
She then drove to Morag’s house in a rage, broke into her house, and threatened her. Acting quite deranged, she said: “You took Amy from me. You and Tulloch. You stole her.”
Luckily, Morag managed to talk Stevie down before any harm came to either of them. Police subsequently arrived to arrest Stevie.
Shetland series 10 episode 4: Stevie Shannon didn’t kill Eadie
At the end of the episode, Amy and Stevie Shannon did reunite on better terms. And we also discovered that Stevie did NOT kill Eadie Tulloch.
Although she had been in Eadie’s garden the night she died, she was only curious to see her again. She said: “I wanted to look at her and see if she looked the same. But she just looked like a wee old woman. I just watched her through the window, and then went back to Amy’s.”
The third set of fingerprints found in Eadie’s house were not a match for Stevie’s.
Robert Tulloch revealed to be a corrupt police officer
Sandy and Tosh came to the disturbing conclusion that Robert Tulloch was a corrupt police officer, and taking bribes.
Knowing the revelation would unsettle Billy, Tosh decided to secretly investigate further. She met with Gina Powell who had previously accused the police of ruining their family. Gina painted a sinister picture of what life was like in Lunniswick under Robert Tulloch’s watch.
Robert had arrested Gina’s late husband Ray, a petty crook, in connection to the robbery of a goods container at Lerwick docks. Although Ray was most definitely with his wife and son on the night of the crime, he was strong-armed into signing a confession.
Meanwhile, Gina was blackmailed into lying, too. She told Tosh that “Lunniswick was Robert’s kingdom”. She added: “Robert framed Ray because Ray had been goading him. Ray was with me the night the robbery took place. But Robert told me it would be better for me [if I didn’t provide an alibi for Ray].
“Robert was tired of Ray. He wanted him off the isles. He made it quite clear I was to help him do that. I refused. But then Robert reminded me that his wife Eadie was the head of family services. One word from Robert and Eadie would start investigating us. He said that kids got taken from their families all the time. I could either stand by Ray, or lose my son David.”
But did Eadie know what her bent copper husband was up to?
Shetland series 10 episode 4: Is Billy corrupt like Robert?
Of course, viewers know that Robert Tullock and Sgt Billy McCabe worked together back in the day. In fact, Robert was Billy’s superior officer. They became friends, and Billy’s wife was also pally with Robert’s wife Eadie.
But was Billy complicit in Robert’s bullying tactics, and corruption? At the end of Shetland series 10 episode 4, Tosh received a duplicate copy of the missing bank statement we saw Billy with in the previous episode.
The statement proved that Robert had paid Billy £10,000 in 2001. It doesn’t look good for our Billy, does it? Not least as he attempted to hide the evidence.
What else happened in Shetland series 10 episode 4?
At the kirk, Alan showed DI Ruth Calder the bruised and battered face of Ethan – thanks to Tom Jameson’s .
Calder made a discovery linking Eadie to young lovers, Ethan and Jess, and the fate of their unborn child. It turned out that Jess had planned to give her unborn child up for adoption, and had been talking to former social worker Eadie before she was murdered…
Lastly, DI Ruth Calder and Ed Tulloch continued with their sizzling chemistry, with Ed admitting he’d love to take her out for dinner.
Ultimately, Tosh and Ruth Calder were no nearer knowing who killed Eadie Tulloch… Ruth herself said: “We have no suspect, and no motive.” Although of course, Robert’s corruption could well be motive enough to take revenge on his wife – innocent or not.
Top 6 bombshells in episode 4 of Shetland
- The Callaghan’s henchman Mitchell left Will Louden for dead.
- Eadie Tulloch’s bank account showed £10,000 from Robert to Billy.
- Stevie Shannon made the call to social services about her sister, but Amy and Stevie Shannon came back together at the end of the episode.
- Stevie Shannon attacked Morag.
- Stevie Shannon didn’t kill Eadie.
- Gina Powell confessed about Robert threatening her with social services.
