In the distance, the sky lit up with a line of fire like a lightning bolt drawn with a ruler. A sonic boom rolled across the bay a few moments later, and Amos had a sudden and intense memory of sitting on those very docks with Erich, watching the rail-gun supply lifts fired into orbit, and discussing the possibility of leaving the planet.

To everyone outside the gravity well, Amos was from Earth. But that wasn’t true. Not in any way that mattered. Amos was from Baltimore. What he knew about the planet outside of a few dozen blocks of the poor district would fit on a napkin. The first steps he’d ever taken outside the city were when he’d climbed off a high-speed rail line in Bogotá and onto the shuttle that had flown him to Luna.

He heard quiet footsteps on the jetty behind him. The discussion was over. The yeas outweighing the nays. Amos turned around and faced the approaching teens. A few of them held improvised clubs. One had a knife. “Not worth it,” he said. He didn’t flex or raise his fists. He just shook his head. “Wait for the next one.” There was a tense moment as they stared at him and he stared back. Then, moving as though they’d reached some sort of telepathic consensus, they drifted away in a group.

Erich was wrong about him being the same. The man he’d once been wasn’t a collection of personality traits. He was the things he knew, the desires of his heart, the skills he had. The person he’d been before he left knew where the good basement booze was brewed. Which dealers had a consistent supply of quality black market marijuana and tobacco. The brothels that serviced the locals, and the ones that were there only to rob thrill-seeking poverty tourists. That person knew where to rent a gun for cheap, and that the price tripled if you used it. Knew it was cheaper to rent time in a machine shop and make your own. Like the shotgun he’d used the first time he killed a man.

But the person he was now knew how to keep a fusion reactor running. How to tune the magnetic coils to impart maximum energy to ionized exhaust particles, and how to fix a hull breach. That guy didn’t care about these streets or the pleasures and risks they offered. Baltimore could look exactly the same, and be as foreign to him as the mythical land of Belgium.

And in that moment, he knew it was his last time on Earth. He was never coming back.