Gideon--a body thief whom Shane thought she had eliminated--escapes from his prison and seeks out the young woman who put him there.
Distressed by his reemergence, Shane, reticent heir to Gideon's stewardship, seeks to avoid him. Then an angel shows up, asking after the Purging, a plague that eradicated most supernatural beings nearly a century prior. Shortly thereafter, a powerful flu strikes the impervious Shane. Gideon realizes the Purging is back to finish the daemons, taking with it many humans as collateral damage. However, Shane wants nothing to do with him, instead trying to ferret out her own via research, a Heavenly weapon, an alternative rock band, and a trip through Gideon's heinous past.