Release Message:  Two astronauts, Hector (Jack Mullaney) and Mac, after breaking the speed of light, accidentally travel back in time to prehistoric Earth. Unable to return, they make friends with the "natives".

Description:  Two astronauts, after breaking the speed of light, accidentally travel back in time to prehistoric Earth. Unable to return, they make friends with the "natives". The astronauts do get to come back to this time, and bring the cavemen with them. They must then learn how to get along in the 1960's.