The book explores the theory that an ancient, advanced civilization existed before the currently accepted historical record and that remnants of this lost civilization can be found in ancient structures, artefacts, and myths worldwide.

The Indus civilization, also known as the Harappan civilization, was one of the largest in ancient history, extending over parts of India, Pakistan, and Afghanistan and containing as many as five million people.

The Bronze Age began in the Ancient Near East roughly between 3000 BC and 2500 BC. The previous millennium had seen the emergence of advanced, urbanized civilizations, new bronze metallurgy extending the productivity of agricultural work, and highly developed ways of communication in the form of writing.

There are more than one hundred uncontacted tribes around the world.