AN: For Trick or Treat 2014.
Samuel Vimes kept a blank look on his face while gazing at the...thing. He took a firmer hold of his baton and spread his stance slightly. It was a bluish blob of a size of small house, and it kept chirping like a tiny canary. Slowly and carefully he kept approaching it, but it kept backing away and reaching for him in quick turns.
When he was finally at a touching distance, it let out a loud chirp and jumped, jumped on top of a three-story building. Vimes let out a curse and started to look how to climb up to it. Luckily there was one half-rotten ladder, missing nearly a quarter of its steps. It was still long enough to reach the roof, but it took undetermined time to climb. Only one step fell under his weight, but Sergeant Littlebottom had had a near heart-attack when it happened. Or at least her voice seemed to carry the sentiment anyways.
When he finally got to the roof, the blob was... either wiggling. Or maybe shaking, it was hard to tell. It's voice was getting smaller and thinner, and it's blue colour was pale enough to look white. Vimes walked up to it, and slowly, gently lowered his hand to its skin. It gave a last shudder, and stilled. Vimes gave it a small pat, and it gave small, questioning chirp.
Suddenly he could hear Archchancellor Ridcully's extremely loud voice down below, followed by a cacophonous crash and some vile curses. After awhile, a face (or more accurately, a pointy hat and then a face) of a young man came up. He looked slightly green on the edges but managed to stumble over the roof's edge.
After a quite embarrassingly long break, where the younger man was trying to catch enough of his breath to talk, the blob started to jiggle up and down in probably excitement. The wizard finally managed to find his own voice to start to explain something about space and letters and rippings, but Vimes just looked at him blankly until he finally quieted down in embarrassment.
Samuel Vimes shook his head sadly. He had known that it was too good to be true to think that wizards and their problems would stay away from his jurisdiction.