Months after mysterious corals drew 99% of humanity into the sea, a band of survivors ekes out a hollow existence on a remote British island. When two people are cast up on the beach, completely blue, but very much alive, the island is thrown into turmoil.

What is the secret behind the mass extinction event... and will this pair of altered humans prove our salvation - or our undoing?

Months after mysterious corals forced 99% of humanity to walk into the sea, a band of survivors eke out a hollow...