In the future, humanity is being evaluated by an alien interstellar community to see if humans warrant membership. The process is taking decades, and humanity is losing patience. In the interim, a mysterious prehistoric object is discovered beneath the Yucatan in Mexico, an object harboring a secret concerning humanity's origins. Accidentally awakened by nuclear explosions, the object seeks to destroy all life on Earth, and only an eminent astrobiologist has any chance of stopping it.