Longlisted for the Women's Prize for Non-Fiction 2025: the profound and life-affirming memoir about finding our way in a chaotic world'A sumptuous, surprising, dark delight' Carmen Maria Machado'Fast-moving, deftly balanced, full of surprises' Guardian's Book of the Day'A bold and original blend of memoir and science' Elizabeth BuchananIf fish don't exist, what else do we have wrong?As a child, Lulu Miller's scientist father taught her that chaos will come for us all. There is no cosmic destiny, no plan. Enter David Starr Jordan, 19th-century taxonomist and believer in order. A fish specialist devoted to mapping out the great tree of life, who spent his days pinning down unruly fins, studying shimmering scales and sealing new discoveries into jars of ethanol.At a time when Lulu's life is unravelling, David Starr Jordan beckons. Reading about Jordan's sheer perseverance after an earthquake shattered his collection, Lulu stumbles upon an unexpected antidote to life's unpredictability. But lurking behind the lore of this mighty taxonomist lies a darker tale waiting to be told: one about the human cost of attempting to define the form of things unknown.This is a story unlike any other you've read before. It's about a very tall man with a walrus moustache, the injustices and unexpected deliverances of the universe, love that strikes like lightning and about why fish don't exist after all.