A vicar with a passion for nature, the Reverend Albert Canning leads a happy existence with his naive wife, Hester, in their sleepy Berkshire village in the year 1911. But as the English summer dawns, the Cannings' lives are forever changed by two new arrivals: Cat, their new maid, a disaffected, free-spirited young woman sent down from London after entanglements with the law; and Robin Durrant, a leading expert in the occult, enticed by tales of elemental beings in the water meadows nearby.

Quickly finding a place for herself in the underbelly of local society, Cat secretly plots her escape. Meanwhile, Robin, a young man of considerable magnetic charm and beauty, soon becomes an object of fascination and desire. Sweltering in the oppressive summer heat, the peaceful rectory turns into a hotbed of dangerous ambition, forbidden love, and jealousy—a potent mixture of emotions that ultimately leads to murder.