In Search of E.J.H Corner the Relentless Botanist John (Kay) Corner left home in 1960, aged 19. He would never see his father, E. J. H. Corner, again. Edred John Henry Corner was one of the most colourful and productive biologists and mycologists of the 20th century. His career began in 1929 as Assistant Director of the Straits Settlements Singapore Botanic Gardens, where he trained monkeys to collect specimens from the treetops of the rainforest, and published Wayside Trees of Malaya, a classic field guide interspersed with his delightful and idiosyncratic observations on plant life. He was key in the creation of Bukit Timah Nature Reserve, a 163- hectare plot that contains more tree species than the whole of North America. When war came, he considered it his responsibility to safeguard the scientific and cultural collections of Singapore during the Japanese Occupation, but was branded by some as a collaborator. Post-war, after heading the ambitious UNESCO Hylean Amazon Project, he returned to Cambridge University and was appointed Professor of Tropical Botany in 1965. There he propounded his theory that the Durian represented an ancestral type of angiosperm tree. He was elected a Fellow of The Royal Society, where he promoted the conservation of tropical forests and led expeditions to the British Solomon Islands and Mount Kinabalu. For the latter, he proposed Kinabalu Park which led to its designation as a UNESCO World Heritage Site. After 46 years, John Corner faces his estranged father in a suitcase marked: ‘For Kay, wherever he might be.’ The letters, pictures and other memorabilia that spill out led him to search for the father he hardly knew, resulting in an engaging and frank biography of an eminent scientist who put science above all, including his family.