Every human being who ever lived wakes at once, naked, hairless and made young again, on the grassy banks of a river that winds without apparent end across an unknown world. Among the resurrected is Sir Richard Francis Burton, the Victorian explorer and linguist, who resolves almost at once to discover who has remade humanity and to what purpose. He gathers a mismatched company, among them the grown Alice Liddell of Wonderland fame, a Neanderthal he names Kazz, the science-fiction writer Peter Frigate and Monat, an alien from Tau Ceti, and builds a boat to travel upriver towards the source. Food and goods issue from metal 'grailstones' along the shore, and death brings only relocation elsewhere on the river, so the real currency becomes power, as tyrants such as Hermann Goering raise kingdoms of slaves. Farmer, who developed the vast Riverworld sequence from an earlier unpublished novel, is less interested in tidy answers than in the friction of history's billions thrown together. Behind it all move the secretive Ethicals who engineered the resurrection. The book is finally an inquiry into free will, mortality and the human refusal to accept a paradise on someone else's terms.