Graham Hancock goes on a global quest, from Cambodia to Egypt, to trace the remains of a lost civilization that passed on its legacy to ancient cultures around the world.

From the Nazca lines in Peru, via the pyramids at Giza, to the Hebridean settlement of Callanish, comes evidence that our ancestors could measure changes in the movement of the stars, sun and moon.

The mysterious statues of huge heads on Easter Island have perplexed scientists for hundreds of years. Why did the inhabitants of a remote, tiny Pacific island carve and place such elaborate statues?