One thing that's concerning me this season is the return of Cassie and Tosh. Don't get me wrong, I love having them back, but you have to wonder why they're back. If last season taught us anything, it's that the show doesn't shy away from hurting Tosh, and in a story centred around the murder of young women, you have to worry for Cassie. It's uncertain yet whether Alan Killick is guilty of anything more than loving someone who didn't love him back, but on an island as small as Shetland, the murderer can't ever be more than a stone's throw away.
