The exit curve from A31 to Av. Joffre had Prometheus crossing the Moselle for the fourth time that minute, finally landing him on the eastern bank where the historical district lay. A half round on the fountain capped circle turned Joffre to Foch, and he was ready to head north toward the centre of the city. As he eased along Rue Maurice Barres, he tried not to think about the irony of passing a penitentiary on his way to commit a crime. He still remembered the stab of guilt he felt the first time he had used this station to…