The Price of Fire. Vol. 2. Children of Leviathan

The Old World burned to the ground, and a new one appeared on its ruins. Technology is forbidden in it; intelligent machines rot in underground shelters; and people fight with swords and spears instead of bombs and rockets. A young knight and an outcast make their way through the enemy lands to return home. If they’re caught—they’ll kill them on the spot. But they have a key to a weapon that can revive the Old World… or destroy it forever.