Evangeline Ames has rented a country cottage far from the London streets where she was recently attacked. Fascinated by the paranormal energy of nearby Crystal Gardens, she finds pleasure in sneaking past the wall to explore the grounds. And when her life is threatened again, she instinctively goes to the gardens for safety.

Lucas Sebastian has never been one to ignore a lady in danger, even if she is trespassing on his property. Quickly disposing of her would-be assassin, he insists they keep the matter private. There are rumors enough already, about treasure buried under his garden and occult botanical experiments performed by his uncle--who died of mysterious causes. With Evangeline's skill for detection, and Lucas's sense of the criminal mind, they soon discover that they have a common enemy. And as the energy emanating from Crystal Gardens intensifies, they realize that to survive they must unearth what has been buried for too long.