This is the fourth and final book of the teen cycle "Through the Looking Glass" by the popular French writer Christelle Dabos.
Thanks to her stubborn studying at the "Friendly Family" school on the multinational ark Babylon, Ophelia finally manages to find her husband, Thorne, in the very heart of the Memorial, where he hid to find a trace of God. To Thorne and Ophelia’s great surprise, he is found… in children’s fairy tales written by a certain Eulalia Duwal.
But if God is Eulalia, then who is that mysterious Other whom Ophelia once set free by going through the mirror? And what is that echo—those strange echoes and odd resonances—that Lazarus, one of God’s accomplices, considers the key to everything?
There is only one way to stop the collapse of the arks: the heroes must find the Other. Ophelia and Thorne continue investigating the echoes and other mysterious phenomena of Babylon, as well as the back alleys of their own memories. They still don’t know that God is about to gain the power she dreams of. Then who will pose the greatest threat to the world: Him or the Other?