He shot the girl first.

"Get out!" he screamed. "Get into the next car!"

Then he shot the boy, and then pivoted and shot the middle-aged man surging off a nearby bench, trying to reach him. The motion of the train and the man's own momentum carried him forward, and as the man's body slid to a stop by his feet, he stepped aside, moving his sights across terrified faces, still shouting at them.

"Now!" he screamed. "Get out!" And to urge them, like cattle, he fired again, and again, and there was screaming now, and the passengers were scrambling over each other, pulling on one another to make for the door at the far end of the car. He fired into them, hitting a woman he thought was moving too slowly.

The car emptied, and the train was still swaying, speeding toward the station.

He turned to the closed-circuit camera in the corner above him and put a bullet into it, knowing that it had already witnessed what he had done. If all was according to plan, the conductor was already contacting the station, and the station, in turn, had begun its emergency response. The evacuation would have begun, the police been notified, Armed Response Units dispatched.

All to plan.

With his free hand, he reached into the backpack and removed the first bottle, turning and throwing it down the length of the carriage. It shattered on a metal handrail, glass bursting, petrol splashing, its scent sudden and almost sweet. He took the second bottle and threw it against the conductor's door, where it smashed. Petrol spattered on his pants and arms, sloshed across the floor, saturating the clothes of the wounded man at his feet.

He heard the door from the adjoining carriage open, and he fired without looking, not caring who, or even if, he hit. The gun was almost empty, but the gun had never been the weapon, only a tool. Even the petrol was only a tool.