As the United States recovers from a terrorist attack on Washington, D.C., and the new president of the United States is an endosym, Amy and Joe Weah travel to the ancient village of Zigda.
There, hidden beneath the Mountain of Darkness, they discover a secret that will change everything they thought they knew about the human race.
Armed with the knowledge of the location of Duncan McDougal, the leader of the endosyms, they travel to Glastonbury, England to elicit the help of the zoutari, members of an ancient Druid cult that has battled the endosyms for thousands of years.
But her task will not be an easy one. With time running out, will she be able to save the world?