"I could see either one," Bella says. "If the prisoners blow themselves up and it looks like the civilians did it, the civilians think whoever had their detonator pushed the button. That person's confused, no one believes them if they say otherwise, everyone thinks they had the stomach to blow up five hundred people, they start doubting their own memory - just a little button, maybe they slipped, maybe they deluded themselves, maybe they repressed the memory? - and you've still got lots of live non-criminal civilians, the city doesn't mass-evacuate out of grief and panic the next time they think it's safe to do so and leave you with a ghost town. If the civilians blow themselves up and it looks like the prisoners did it, there's a crackdown on the prisoners, maybe you find your next stint in prison more interesting, political interests that care about looking after the welfare of prisoners get into fantastic fights with political interests that don't - I guess they do that in either case. Maybe a guard on the boat presses the button and you get most of the psychological benefits - so to speak - against him that you could've against a civilian who doesn't remember pressing hers in the other scenario. And it doesn't matter who pushes the button if they all explode. From the outside, from the perspective of everyone left alive, it looks like they both did it at the same time. It especially doesn't matter if you just explain the trick after the fact - then no matter what the buttons actually did, you get to leave everyone paralyzed with indecision if they get caught in one of your pranks." She regards him steadily. "I think I'm glad you're in jail."