On the death of her master and protector, Arundill the alchemist fled from the citadel of the order of the Shadows where she was detained. The obscur necromancer Ravan comes to her with the hope that she will be able to help her discover "Le Havre", a place where rebel Magi would have found refuge. They must win this place if they want to escape the assassin whom the Order sent to pursue them.