Vimes had acquired . . . a companion. The dwarfs had one name for it: the Summoning Dark. And they had any amount of explanations for what it was: a demon, a lost god, a curse, a blessing, vengeance made flesh, except that it had no flesh other than the flesh it borrowed, a law unto itself, a killer but sometimes a protector, or something that no one could find the right words for. It could travel through rock, water, air and flesh and, for all Vimes knew, through time. After all, what limits can you put on a creature made of nothing?
