As the Shetland Isles prepare for the tourists coming for the Up-Helly-Aa festival Jimmy Perez investigates the murder of elderly Mima Wilson,shot dead outside her croft. An archaeological dig was taking place on Mima's land and team member Hattie James tells Perez Mima was upset when a piece of skull was unearthed by Mima's niece Jackie Haldane. Perez learns from Jackie that Mima was also unwilling to sell her land to developer Duncan Hunter,in which she was opposed by her son Joseph.Jackie's drunkard son Ronald is also a suspect and is beaten up by mystery attackers.Perez also discovers that in World War Two Mima's husband and Jackie's father Andrew,now an invalid,helped refugees from Norway escape the Nazis,one bearing the same surname as the dig's leader,Paul Berglund. Then Hattie is killed as she is about to tell Perez something.

When no other prints are found on the knife that killed Hattie suicide is the first thought as her mother says she was prone to depression. However Perez discovers that she had had a fling with Berglund,which could jeopardise his dig. Perez matches a necklace Hattie was holding to one in an old photograph of Mima with Per Lungstad,one of the Norwegian escapees in the war. Per was supposedly drowned but no body found. However the list of suspects grows as Perez discovers that Berglund was also having an affair with Ronald's wife Anna,a fact Mima could have seen and that Ronald was in debt to Duncan Hunter.Ultimately Perez learns that Mima was upset to see the body being dug up on the archaeological site,reminding her of a secret love affair from over sixty years ago. Ailing Andrew Haldane supplies Perez with some of the facts but,as the crowds gather for Up-Helly-Aa Perez must work out the precise link between past and present and the reason for Mima and Hattie being murdered.

DI Perez and his team reopen a past case to solve a present day murder of a young girl, Catherine Ross who's body was found on a secluded beach. The obvious suspect is someone that Perez doesn't want to pin the blame on as he fears there would be a witch-hunt to deal with.

Detective Inspector Jimmy Perez believes he and his team are finally closing in on the killer as they discover what 17-year-old Catherine Ross was hiding from everyone in the hours before her death.

An old journalist friend of Perez's, Jerry, dies in a suspicious car accident. However Jerry had been away from the Shetland's for a while so his motives for coming back are unclear. Perez suspects his ex partner Evie may have been involved and she is about to get remarried.

A second brutally murdered body is uncovered, Perez begins to wonder if the two murders are linked by the same corruption or just by the same woman. He receives a surprise visit from Annabel a woman claiming to be Jerry's fiancée and hands over a memory stick she was given by him weeks ago. On the memory stick he uncovers emails giving him more evidence as to why someone might want to murder Jerry.

Perez makes a return to the Shetland island of Fair Isle following the murder of a scientist. Tensions increase after a storm on the mainland forces him to work in complete isolation with all of the murder suspects being forced to stay on the island in close proximity to each other.

Perez continues the murder investigation but he is running out of time because number one suspect Peter Latimer is critically ill in hospital and he is forced to wonder whether the murderer is still on the loose.