Shetland: Blue Lightning (Part 2 of 2)

Part two of two. Time is running out for Perez and Tosh as their prime suspect lies critically ill in hospital, but it's unclear whether the fire that put him there was a drunken accident or if he was the second victim of Anna's real killer. The DI turns his attention to Finlay Caulfield regarding the photos of Anna on his camera, and while it becomes clear he was obsessed with her, it may not be enough to charge the stalker with her murder. There are still so many unanswered questions - until Sandy spots something on the CCTV footage that takes the investigation in a new direction. Douglas Henshall stars, with John Lynch, Bill Paterson, David Ireland, Alison O'Donnell and Steven Robertson