A child goes missing, taken from her mother by a powerful family. Soon after, the father of the girl is banished for violating the code of the tiny Cornish hideaway.

Emma Thorne has come to the edge, not knowing if her daughter is alive or dead. The village offers no clues, and gives away no secrets. In desperation, she enlists the help of a local private investigator, holding out hope that Lauren can be found.

But the investigator, Jake Stevenson, knows how to find missing people. He's done it before, travelling to places beyond our understanding. But where can he begin his search, and what clues can the village of Towan Point offer him?

In an ancient lighthouse, cut off from the outside world, a doorway pulses gently in the darkness. A doorway that no one comes out of.

What lurks on the other side, and can he discover the secrets beneath the sea?