From the New York Times bestselling author of Incarceron comes an “engrossing, enthralling” (New York Times) world where a powerful artifact holds the key to unimaginable worlds and untold power. “Those who loved the genre-mixing fun of Colfer’s Artemis Fowl will find this to be right up their alley.”—BCCB, starred review “Fans of Kady Cross, Cassandre Clare, and Doctor Who will be enthralled with this must-read title.”—VOYA, starred review The obsidian mirror. Its power is great and terrible. Men have been lost in it, the dead brought back to life through it, and the future annihilated by it. Or this is what will happen unless the mirror is destroyed. Three people seek the mirror: the first has been sent from the future to shatter it; the second will protect the mirror at all costs, obsessed with its power; and the third needs the mirror to find a murdered father and restore his life. But only one can succeed . . .