A dying scientist (Dana Andrews) trying to use the earths magma as an umlimited source power creates a crack in the earths crust after dropping a nuclear bomb into a deep hole. A rival scientist (Kieron Moore) and rival for his wife's (Janette Smith) affections then has to try and stop it. Whilst there may not be much truth to the science, it is entertaining for a 1960's sci-fi film and some good action scenes including an impressive, for the time, final sequence.
Dana Andrews
Kieron Moore
Alexander Knox 
3/5