The earth continues to tumble slowly head-over-heels as President Lloyd Sinclair embarks on a mission to save mankind from total annihilation. The greatest mass extinction event in the planet's history has begun, and his success will hinge on the existence of the twilight zone, a narrow latitudinal band that circles the globe just north of the equator. This is where a life-sustainable environment might subsist-but it will only support less than two percent of the 7.4 billion inhabitants on the planet. Neither does it pass through North America. The world watches in astonishment as Sinclair begins to act in a bizarre manner, but his efforts to suppress the tumble while he introduces a plan to control the twilight zone starts to crumble. Thelma Carpenter believes there is an association between the satellite failures, the extreme heat wave, and the president's strange behavior, and she begins to seek a connection. Her boyfriend, Cobra, is skeptical of her suspicions, but he also knows not to underestimate her abilities. It is rare she is wrong.