"The things we do make echoes. S'pose, f'rinstance, you stop on a street corner and admire a brilliant fork of lightning—zap! Well, for ages after, people and things will stop on that very same corner, stare up at the sky. They wouldn't even know what they were looking for. Some of them might see a ghost bolt of lightning in the street. Some of them might even be killed by it. Our existence deforms the universe. That's responsibility."