The City of Mirrors (The Passage, Bk. 3)
In the wake of the battle against The Twelve, Amy and her friends have gone in different directions. Peter has joined the settlement at Kerrville, Texas, ascending in its ranks despite his ambivalence about its ideals. Alicia has ventured into enemy territory, half-mad and on the hunt for the viral called Zero, who speaks to her in dreams. Amy has vanished without a trace.
With The Twelve destroyed, the citizens of Kerrville are moving on with life, settling outside the city limits, certain that at last the world is safe enough. But the gates of Kerrville will soon shudder with the greatest threat humanity has ever faced, and Amy--the Girl from Nowhere, the One Who Walked In, the First and Last and Only, who lived a thousand years--will once more join her friends to face down the demon who has torn their world apart . . . and to at last confront their destinies.