A family on a remote island. A mysterious woman washed ashore. A storm gathering force.

Dominic Salt and his three children are caretakers of Shearwater, a tiny weather-lashed island that is home to the world’s largest seed bank. As Shearwater risks being lost to rising sea levels, the island’s researchers have fled, and only the Salts remain.

Until, during the worst storm in living memory, a stranger washes ashore. The family nurse the woman, Rowan, back to strength, but it seems she isn’t telling the whole truth about why she’s there. And when Rowan stumbles upon sabotaged radios and a recently dug grave, she realises that she’s not the only one on the island with a secret.