With Joe now promoted Vera and her new sergeant, Aiden Healy, investigate a fatal explosion at a caravan park which killed Deena Viner, sister of the park's owner Jim. Deena and her friend Sally had been part of the stag night party for Ryan, boyfriend of Jim's daughter Claire, and, after evidence that Sally had slept with Ryan, Claire tells Vera he was growing cannabis in the caravan that was destroyed. Sally and Ryan both benefit financially from Deena's death but Deena was also involved with Ryan's teen-aged brother Riley who has no alibi for the murder. The mystery deepens when Vera is told that Deena was killed and then placed in the caravan before it blew up. With the park in financial difficulties largely caused by Deena and a resentful resident in the trailer next door Vera has several likely suspects before she can solve the case.