Cruising for days under the ice, Seaview surfaces to find the sky is ablaze thanks to the Van Allen belt catching fire. Nelson races to Washington to confer with fellow scientists and hatches a plan to detonate a nuclear device into the atmosphere and extinguish the fire. Weber, a Fellow scientist, feels they should do nothing and allow the fire to burn out. Nelson disagrees and takes Weber and two others aboard Seaview to decide the course of action as the sub races to the firing point. However, Weber is determined to stop Nelson and is willing to kill to do it!
Elenco: Richard Basehart , David Hedison , Robert Duvall , Terry Becker , Del Monroe , Paul Trinka , Richard Bull , Robert Dowdell .