"Dominic Salt and his three children are caretakers of Shearwater, a tiny island not far from Antarctica. Home to the world's largest seed bank, Shearwater was once full of researchers, but with sea levels rising, the Salts are now its final inhabitants. Until, during the worst storm the island has ever seen, a woman mysteriously washes ashore. Isolation has taken its toll on the Salts, but as they nurse the woman, Rowan, back to strength, it begins...