"Is plastic all right?" said the gangly high school girl at the end of the checkout conveyor, and all at once Derek realized that plastic was not all right, that plastic was one of the pieces of the suicidal petroleum dependency the humans had developed, and that he himself was in fact not human, that one of the things he was on Earth to do, having drawn his consciousness down into a fully human body from hundreds of light years away in order to warn and inform humanity, was to wean humans from their fossil fuel dependencies and usher them--propel them, really--into a more harmonious and energy-rich future.

His race were adept at these occupations of other life forms, but in some cases it was difficult to keep his own mind going instead of the occupied creature's mind, and in the human he had found himself drowned in sensation and emotion the moment he'd occupied. He was only surfacing enough to be lucid every few years. This could be disasterous, because between impending ecological disaster and the Nithing fleet ranging ever closer to Earth, the end of things was rushing toward the humans much more quickly than they realized. If they didn't have his help--

"Sir? Is plastic OK?'" said the girl, and Derek jerked back to himself from wherever he'd been woolgathering.

"Sorry," he said, smiling. "Long day."

The girl's hands hovered over the groceries. Derek's tub of peppermint ice cream was rolling in place, held there by the bag of potatoes. "So, the plastic?" said the girl.

"Oh--fine," Derek said. The girl began sorting the items into the bags with a sort of reckless competence. Derek reflected again that he ought to get those environmentally-friendly, reusable grocery bags, so as not to keep using up plastic unnecessarily. But it was OK. There was plenty of time for that.