At the great atomic plant in Kimberly, a congressional committee makes a surprise inspection raising the level of the men's tension even higher than it has been. By midday there have already been minor accidents but in the giant nuclear converters which are at the heart of the project work goes on at desperate speed. Until converter Number four fails disastrously. Jorgenson, the supervisor of the technical team and his crew had been running through a new and unstable isotope when the walls of the reactor gave way. The process of fusion is suddenly out of control...and half a continent may be destroyed in a "peace-time" disaster which will not only sacrifice millions of lives but will destroy the possibility of controlled nuclear power forever. Jorgenson, the crew chief has survived the accident and is the only man who knows how to stop the runaway reactor. But Jorgenson is trapped inside that reactor, unable to communicate. He must be found and saved quickly in a desperate race...or risk the globe itself.