When his beloved only daughter goes missing, millionaire entrepreneur Walter van Dam calls in a team of experts – including free-climbers, a geologist, a parapsychologist, even a medium – to find her . . . for Anna-Lena has disappeared somewhere within a mysterious cave system under the old house the family abandoned years ago. But the rescuers are not the only people on her trail – and there are dangers in the underground labyrinth that no one could ever have foreseen