Hale, an American astronaut dies and is reincarnated with other persons who have lived throughout all of human history and end up on a mysterious planet called 'Riverworld'. The humans are left to their own devices and create tribal fiefdoms and succumb to brutal wars and raids. A mysterious race of hooded 'beings' oversee them - sometimes intervening, but their motives are unknown. Anyone who has ever lived and died on Earth comes here rather than 'the afterlife', even an extra-terrestrial call Monat, who had the unfortunate luck of dying on Planet earth in 2039. Hale leads a revolt and joins with others on a large boat to explore this mysterious new world.

Returning to Rome after 3 years in the field, General Marcus Vinicius meets Lygia and falls in love with her. She is a Christian and doesn't want to have anything to do with a warrior. Though she grew up Roman, the adopted daughter of a retired general, Lygia is technically a hostage of Rome. Marcus gets Emperor Nero to give her to him for services rendered