Shetland's Tosh and Donnie in heated clash as Calder receives warning

And Tosh's partner Donnie also expressed his disbelief that one of his close friends was ever considered a suspect – even though the police had every reason to initially believe that he could have been involved in his wife's death.

And that continued in tonight's episode (27th November).

Not only did Tara lambast Tosh for doing her job when she enquired about Annie accompanying her on a hospital visit, Donnie also had some choice words for the detective.

"What the hell's wrong with Tara?" he said after initially giving her the silent treatment when she returned home.

"It's work, Donnie," she said. "I can't talk about it, OK?"

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But he wasn't satisfied with her response, and proceeded to give her a hard time for "upsetting" Tara.

"No, it's not OK," he replied. "You cant keep using that as an excuse to go around pi**ing everyone off. These are our friends, Tosh. We know these people."

But she was quick to remind him that, as much as we think we know the people in our lives, everyone has secrets. And when someone is killed, it is the job of individuals like Tosh to pull back the curtain, however awkward and unpleasant it may be.

"Well, to be honest, Tosh, I don't know how you can do your job," he spat back.

But she refused to back down.

"I am trying to find out who killed Annie, and I won't apologise for that," she said with finality.

Donnie then walked off, leaving a very dejected Tosh on her own.

O'Donnell previously told RadioTimes.com that the investigation throws Tosh and Donnie's partnership "into a bit of jeopardy".

"Like most relationships, they do have challenging moments, but this felt like a different sort of thing," she explained.

"This is a bit more profound and fundamental to what their relationship is and how they both see each other, and how they see the relationship and their life in this small community, and what the priorities are.

"And I don't think that Tosh is going to come out of this unscathed. At the conclusion of the series, her relationships are not what they were when the series begins."

But alongside that ongoing discord, there was a new development in episode 4.

DI Calder received a call from an old acquaintance in the force regarding Euan Rossi, who was a friend of Annie's and had worked with her as an analyst in the intelligence service, or so he previously told the detective.

But when Calder informed him that Rossi was in Shetland, he warned the detective to "bring him in".

"I don't know why he's there or what he's doing, but Rossi's dangerous," he added. And sure enough, the suspicious party was collecting a gun at that very moment.

It seems Ruth's suspicions about him were right all along...

Shetland season 9 continues on Wednesday 4th December at 9pm on BBC One and iPlayer. Ann Cleeves's Shetland novels are available to buy now.

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