I'm having a logic-based plot hole problem. Here's the gist: Aliens show up in Washington DC during WWIII and say, "Hey guys, we need batteries/research subjects/slaves/whatever and you're perfect. We only need, like, ten million, can you spare that many, or are we going to have to use force?" And DC says, "Sure! Take Pakistan, we don't like them." And the aliens say, "Great!" and use their tractor beam or whatever to snag Karachi and three miles of dirt, leaving a giant circular hole in the ground with sheer walls. They drop Karachi on one of the moons orbiting their home planet, and... never come back. I need my MC to find an empty (except for one remaining alien) place under Karachi (with bodies? without bodies? I'm not sure how horrifying I want this to go), but why would they just abandon them there? There's an obelisk (capacitor) in the middle of the city from which the aliens collected energy, but ships don't come by anymore, because the people don't remember that they were kidnapped by aliens. It's been about 3,000 years. I don't want there to be a mass die-off or great war, 'cause I want them to come back at some point. Here's what I'm thinking right now, but I'm too close to tell if they make sense. 1) The capacitor holds 3,000 years' worth of energy. But won't they need energy more frequently than that? 2) The obelisk gets all thunder-and-lightning every year, which is New Years' Day for the humans, but is actually the capacitor transferring its energy to the planet. The remaining alien is a maintenance guy. I'm not sure this makes electrical sense. Don't you need a wire to do this? Wouldn't it electrocute the whole city? 3) They found a better source of energy shortly after they took Karachi, and cut their losses, leaving the humans to die (there's no agricultural land on this island). But how did they stay alive for 3,000 years? And why would Last Remaining Alien be there? 4) Don't explain it. If I don't draw attention to this plot hole, maybe nobody will notice. So that's what I got. What do you think?