Pest presents the bizarre events that lead a new, parallel life for a man named Chalo as a wild yak living in the Himalayas.

Chalo the man is recruited by a latter day prophet named Grant to design and build a campus on Catalina Island, where initiates will be trained to receive a celestial visitor, the "Ancient Newborn." Chalo the yak reflects on his human past while the annual rut looms ominously nearer and nearer. The struggle to fund and construct the campus is complemented by the psychoactive changes of the yak breeding cycle, and the mating battles that Chalo will have to participate in. Both involve creating something that will outlast Chalo's individual life, and give it meaning. Both will also involve telluric forces, demons recruited by Grant to overcome sinister fiduciary magic, which cross-link the two halves of the story.