Alasdair and Jean are making a deliberate effort to put together a relationship. Leaving Edinburgh to the crowds attending the annual Festival, they move into the caretaker's cottage of an old and spooky castle near Rosslyn Chapel. Rosslyn has been made so famous by The Da Vinci Code that only tour groups are admitted. It's a medieval church where the Holy Grail or the treasure of the Knights Templar is rumored to be hidden. Ferniebank Castle includes a small chapel that's very similar and obviously related to Rosslyn, but is off the beaten path. Or so they think. Even before Jean meets Alasdair at Ferniebank, she hears that trouble is brewing there and in the nearby village of Stanelaw: a local councillor has disappeared, a precious artifact has been stolen, and the castle's former caretaker has died under circumstances that make Alasdair's police-whiskers twitch. It's a bad time for this sort of thing to be happening, since the owner of a popular New Age travel company has just bought the chapel and its healing well, intending to build a spa there, something that will revive the village economy. As though Jean and Alasdair's plans aren't thrown enough of a curve when the New Age guru turns out to be his ex-wife, other crimes and then another death occur right on their doorstep. And everything seems to track back to the former Mrs. Cameron. Even though Alasdair is no longer a formal member of other police force, he and Jean must roll up their sleeves and wade in to yet another mystery.