Sam threw himself violently to his left. He felt the bullet snag his long coat. The smell of propellant harsh and accusatory in his nostrils, he vaulted over the climate control unit onto a lower level of the roof. He ran toward a workshed that offered safety only a few meters away. Her second shot gouged the wall of the shed as he reached it. Sharp fragments of brick spattered into his cheek. He threw himself forward and down, hoping that the sudden maneuver would spoil her aim as he tried to get out of her line of fire. It was a vain hope. His body twisted as he felt a slug slam into his shoulder. Striking the rooftop out of control, he scraped more skin from his already lacerated cheek. He tried to push himself up, but the muscles of his arms failed and he collapsed. His injured arm was numb and cold. He managed to roll over onto his back as she approached him, gun held ready. Her eyes were sad, but her jaw was clenched with determination.