The book proposes that what the authors believe to have been stellar observatories (such as the first wooden Stonehenge) in Britain, and structures in the Boyne Valley in Ireland, show sufficient knowledge to be able to predict prescribed solar, lunar and venusian events and cycles, such as solstices and equinoxes.

The authors suggest that chambers (souterrains) found in Britain might have been attempts to build shelters to be sealed against tsunamis that would have been caused by a cometary impact in the sea.

Prof Archie Roy (an astronomer and psychic researcher) and Robert Lomas gave a joint talk about technological possibilities in Megalithic society at the 2000 Orkney International Science.

Tim Schadla-Hall, archaeologist and editor of the journal Public Archaeology, has cited the book as an example of pseudoscience, in which the authors "quote established academics in such a way as to make it seem as though they support their arguments".

"[5] Mike Pitts, archaeologist and journalist, says that the book contains "what we might politely call a radically alternative approach to Grooved Ware pottery" and notes that the book's bibliography contains "such items as Myths and Legends of Australia, Robert the Bruce and The Pleistocene Elephants of Siberia, but not a single primary archaeological source for England (where, it has to be said, a great deal of Grooved Ware has been found).