THE FOURTH series of BBC crime drama Shetland is set to launch next week - and anticipation is decidedly high.
The six-part series will air from Tuesday (13 February) on BBC One and it focuses on a Shetland man returning home after having a historic murder conviction overturned.
The long-awaited series will again feature all the familiar faces - such as Douglas Henshall as Jimmy Perez and Alison O'Donnell as Tosh - and plenty of stunning landscape shots.
Also returning is Sandy Wilson, who is played by Shetland native Steven Robertson.
The acclaimed third series, which for the first time enjoyed a plot which deviated from the Ann Cleeves novels the story is based on, was watched across the world on TV and on streaming service Netflix.
Robertson, who originally hails from Vidlin, told Shetland News that he always believed the series - which first aired in 2013 - could become a big hit.
"Quietly, in my own way, I have always felt that this show had every chance of doing absolutely everything that it has achieved," he said.
"I don't want to sound like I'm being wise after the event, and that's not something I would have ever said out loud until after the third series was aired and we were getting the kind of feedback we were getting.
"I always thought that the elements within the show would make it a good television show. That was one of the reasons I was incredibly keen to be involved in it."
Also returning to the show is writer David Kane, while Lee Haven Jones (Vera) and Rebecca Gatward (EastEnders) are on directing duties.
This new series sees Robertson's character Sandy intertwined in the main plotline by virtue of his friendship with the family of a woman who was killed 23 years ago.
"He knew the victim - they were all sort of young people together, they'd have been in their mid to late teens, a whole crowd of friends," the actor said.
"They would have been out at the same parties, gone to the cross together at the weekend. Sandy knew the lass and her murder would have been a big part of his life, and he still knows her family, including her twin sister, very well.
"So there's an awful lot of conflict for him, because if the police had gotten it wrong, and this man is indeed innocent, then who was it that actually committed this murder? Are they still in the islands - was it somebody local, could it have been somebody he knew?
"But on the other hand, if this man has managed to get out just on a technicality because the case had maybe been mishandled in the past, have we now got a killer back on the island?"
A particularly redeeming factor of Shetland's success for Robertson is the positive impact it is had on the isles tourism - despite its often dark and morbid storylines.
Many visitors cite the programme as having played a big part in their decision to travel to Shetland, while it isn't uncommon for people to look out show landmarks such as Jimmy Perez's waterfront house at the Lodberries at Lerwick.
"I've always hoped that if it would do as it has done, then I have never understood why it would only ever be a good thing for Shetland," Robertson said.
"You get an hour a week for six weeks...every time the camera swings across a beach or looks out over a cliff, that is Shetland. That is the scenery and in my opinion it can only be a good advert for Shetland."
The first part of the six hour-long series will air on BBC One on Tuesday at 9pm.