England, 1911. The Reverend Albert Canning, a vicar with a passion for spiritualism, leads a happy existence with his naive wife Hester in a sleepy Berkshire village. As summer dawns, their quiet lives are changed for ever by two new arrivals. First comes Cat, the new maid: a free-spirited and disaffected young woman sent down from London after entanglements with the law. Cat quickly finds a place for herself in the secret underbelly of local society as she plots her escape. Then comes Robin Durrant, a leading expert in the occult, enticed by tales of elemental beings in the water meadows nearby. A young man of magnetic charm and beauty, Robin soon becomes an object of fascination and desire. During a long spell of oppressive summer heat, the rectory at Cold Ash Holt becomes charged with ambition, love and jealousy; a mixture of emotions so powerful that it leads, ultimately, to murder.