As a child, Chris Thorogood dreamed of seeing Rafflesia - the plant with the world's largest flowers. He crafted life-size replicas in an abandoned cemetery, carefully bringing them to life with paper and paint. Today he is a botanist at the University of Oxford's Botanic Garden and has dedicated his life to studying the biology of such extraordinary plants, working alongside botanists and foresters in Southeast Asia to document these huge, mysterious blooms. 'Pathless Forest' is the story of his journey to study and protect this remarkable plant - a biological enigma, still little understood, which invades vines as a leafless parasite and steals its food from them.