Anthony Fennell, an Irish journalist and playwright, is assigned to cover the underwater cables that carry the world's information. The sum of human existence-words, images, transactions, memes, voices, viruses-travels through the tiny fiber-optic tubes. But sometimes the tubes break, at an unfathomable depth.
Fennell's journey brings him to the west coast of Africa, where he uncovers a story about the raw human labor behind the dazzling veneer of the technological world. He meets a fellow Irishman, John Conway, the chief of mission on a cable repair ship.
The mysterious Conway is a skilled engineer and a freediver capable of reaching extraordinary depths. He is also in love with a South African actress, Zanele, who must leave to go on her own literary adventure to London.