A young girl named Kitty, only daughter of Charles and Jane Evermore, a rich and respected couple, mysteriously disappears one afternoon from the family home in the Gloucestershire countryside. The police are baffled, as there are no traces of Kitty's whereabouts or clues as to how or why she vanished. Increasingly obsessed by a deep pond on a neighbour's land and the ramblings of a mysterious Irishman, her father is determined to search on alone...