After only ten days on planet Earth, the quasi-immortal Edrinavinski were in a very bad mood. Nuking them had been not just militarily ineffective but also, apparently, bad manners.
        "We are leaving," they said wrathfully. "And you - you will suffer the doom of the asterisks."
        They left, and humanity waited to be engulfed by an avalanche of asterisks, the doom which the Edrinavinski nanotechs were already constructing.
        But nothing happened.
        Ten years later, a repairer of antique watches by the name of Julius Spruce found the first of them inside a watch case. The asterisk was gray, metallic, insoluble - virtually indestructible. Over the next two decades, a dozen more were found. Mathematicians charted the figures.
        "At this rate," the world president announced, "the planet will be entirely covered with asterisks in no more than two and a half thousand million years."
        The Edrinavinski believed that revenge is a dish best eaten very cold indeed.