In 2007 Mary O'Malley made a voyage on the Irish marine research ship the Celtic Explorer. It took her far out into the Atlantic, and it returned her to a self and a country made strange. Valparaiso, a collection begun at sea, is a book of searches and discoveries, plumbing oceanic depths and returning to a shore that marks the start of possibility'. The surge and swell of the sea sounds in it, a place of wonders where the imagination is freed. What would sing in me is the deep ocean.' As the scientists chart a course dictated by the demands of research, as Ireland is careering from boom to bust, Mary O'Malley explores the science of going under and staying afloat. She returns to an altered place, and is herself changed by an odyssey that has taken her around the Atlantic and Europe, into her past and back to a kind of homecoming.