A caravan of travellers crosses the vast, humid plains and dense forests of central Africa, confronting searing heat, wild animals, and hostile villages; they rescue a ten-year-old boy, Llanga, from would-be captors and take him into their care, where he learns local languages and bonds with his rescuers. The narrative follows their caravan's progress, the practical routines of camping and sentries, debates over routes through impenetrable woodland versus detours, hunting and encounters with cannibal tribes, and the tensions and solidarities that arise during a long, hazardous expedition.