Hell's First Army has been preparing a thousand years to reign terror upon this Earth.

For centuries Deborah O'Mara and her siblings have been faithful followers of their brethren in Heaven. After Hell murders an Archangel, Deborah begins to question her very mission as a Guardian.

Rescuing a Sentinel means Deborah will have to shatter The Accord reigniting an age-old Celestial War. She must choose between love and loyalty and find the strength to live with the consequences.

Battling new enemies, forging desperate alliances, and burdened with a soul-crushing betrayal, Deborah is tempted to pursue the path of the Fallen. Her family races to intervene, but they may be too late to stop her from becoming...HELLBOUND.