Caro Kingswood answers a plea from her half-sister Sancha and travels to Spain to design a new garden. At first she has a blissful time at the Palace of the Fountains. The charismatic Joe Spenser appears there and, as he courts Caro, persuades her to reconsider her tangled feelings about desire. Gradually Caro becomes aware that her sister Sancha's marriage is in trouble. Ann Grant, hired by the family to catalogue their collection of Toledo swords and knives, has disappeared, and Sancha suspects her husband Felipe. Soon Caro uncovers a maze of dark family secrets. Worse, Joe tells her that Ann was his beloved sister, and he has persuaded the family to admit him so as to find out what happened to her. So was his interest in Caro real? Matters come to a head during a local fiesta, when the real murderer of Ann Grant targets Caro herself.