Hancock has virtually cornered the market in this kind of speculative writing, and his reputation as the New Age answer to David Attenborough is well earned. Much of the ancient world inherited by our ancestors now lies under water after melting ice caps flooded vast areas at the end of the last Ice Age. New advances in geology and marine technology mean that the great archaeological finds of this coming century will more than likely be found under the oceans. It now looks likely that large populations of early humans were obliterated from the historical record by this catastrophe over 10,000 years ago. But who were these populations: hunter-gatherers or more sophisticated peoples? Hancock applies his customary imaginative speculation on a quest to find some of the answers.