Deep in the rugged mountains east of Seattle, Washington a religious group known as the Shepherds are assembling behind the walls of a well-secured outpost. Mount Cathedral has become the site of a worldwide pilgrimage as Ascension Day approaches, and private detective Tim Brooks and Special Agent Alan Corley are attempting to stop the shadowy ceremony. As tensions mount, two lieutenants grab for power and cause dissension within the ranks. Several members disappear and others are jailed. Violence erupts between two factions as the final assembly number is leaked. Now a covert military operation, designed to destroy the Shepherds once and for all, unfolds outside the gates during the noblest time in the cult's long, remarkable history. Mount Cathedral is more than just a retreat for the members. For the messiah, the elders, and a young boy named Eli, it is a place where doors to other worlds are opened.

And where those who are talented enough to ascend, come face to face with evil.