When Julia's gran, Dot, wins an all-inclusive spa trip to Scotland, Julia finds it difficult to refuse the offer of a relaxing week away from her cafe. Along with her sister, Sue, they pack up her tiny vintage car and drive all the way from Peridale to Seirbigh Castle, ready to be pampered. The last thing Julia expected was to be caught up in another murder investigation, but when the cruel owner of the family-run spa, Henry McLaughlin, is shot dead, she can't resist ditching the facemasks and massages in favour of cracking the case. Julia quickly befriends the young cook and talented-baker, Blair, and acquires a job in the kitchen so she can observe the strange family in the wake of the murder. Henry's wife and children are acting suspicious, and with an incompetent young Detective Inspector on the case, Julia makes it her mission to discover the secrets held within the ancient walls before Seirbigh Castle claims another victim.