A certain gifted engineer accepted the Theory of Evolution until he wandered by chance into a museum. In that museum was the skeleton of a dinosaur, and the skeleton got him thinking and enquiring . . . with terrifying results.

Attempts are made on his life and then, in a horrifying time-shift, he finds himself naked and unarmed in the distant past . . . facing one of the very creatures which had aroused his interestùa dinosaur!