A spellbinding story for fans of The Essex Serpent , Susanna Clarke, Emilia Hart and The Northern Lights . Prepare to be transported to a world of forbidden books, trade wars, colossal devilfish with uncanny power and clattering sea creatures in the shape of humans . September, 1790. Greenwich. William Godsalve is a Clerk in The Sea Library: a four-hundred-year-old white marble institution devoted to collecting knowledge of the sea, and protecting people from its unruly power. When an otherworldly seasickness begins to spread and dangerous book is stolen from the Library's most hidden collection, William is sent home to the devilfishing town of Calderness to investigate. There, he discovers Agnes, a schoolteacher hiding seasick children from the authorities - and connections between this strange seasickness, the Library, the devilfish and William begin to float to the surface . From the Sunday Times bestselling author of The Cautious Traveller's Guide to the Wastelands comes a gloriously imaginative new novel about secrecy, freedom and humanity's fragile relationship to the natural world.

Can anyone control the tide?.