"It stands for artificial intelligence. It's a program, as opposed to a person, who happens to think for itself." Senku paused a moment. "I don't know if any of that means anything to you. Quite a few people aren't from technological societies so they don't always know these things."

He considered that for a moment. "It varies depending on the mission, and which part of the mission you do. There was one, two missions ago, and a lot of people were injured. It was a total mess. The base camp we were at got attacked. Couple of us got injured dealing with the stations outside of that. It's the first one I've witnessed where things got so bad. I've heard, since then, that there have been casualties before. We can't really die though, due to what's tying us to the train, so we come back, but as for the long term effects, we have no idea."