Shetland returned for another "tense" instalment with its penultimate episode on Wednesday night.
The latest chapter of the crime drama saw DI Jimmy Perez inch closer to finding out who killed lawyer Alex Galbraith.
Viewers also saw the aftermath of DS Alison “Tosh” McIntosh finding out that DC Sandy Wilson leaked confidential crime scene photos.
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The sixth series of the cult show has continued to impress fans, with many taking to Twitter to share their enthusiasm.
One wrote: "Brilliant penultimate episode of #Shetland tonight. Can’t wait for next weeks finale."
"Ooft, another tense one," a second viewer shared.
Meanwhile, a third fan called the show "a superb crime drama" that "just gets better and better".
However, it was the storyline involving Duncan and convicted murderer Donna Killick that had most people talking.
Donna, who was granted compassionate release from prison in the first episode of the series after being diagnosed with a terminal illness, decided to end her life - and enlisted Duncan's help.
Before they did so, however, she asked her former lover to post a letter off to her solicitor.
Many viewers couldn't believe Duncan didn't open it to see what it said, and shared their theories on the social media platform.
One fan speculated: "She wants to implicate Duncan in her assisted suicide as her last act of revenge. Such a vindictive, unpleasant character."
A second tweeted: "Oh Duncan! Should’ve read that letter first!"
Another said: "Did that letter to Donna's Solicitor say she thinks Duncan wants to murder her?"
"She's definitely sealed Duncan fate in that letter," a fourth viewer commented.
A fifth wrote: "There's no way I would have posted that letter without steaming it open first. Duncan's never been the sharpest knife in the drawer has he?"
Shetland returns for its final episode of series six next Wednesday at 9pm.
