Much as I would love to have come up with the Discworld, I sadly didn't.
Commander Samuel Vimes was suspicious*. There was something baffling afoot, he just knew it. And he intended to find out what it was. It would require careful observation, diligent gathering of evidence, and extreme discretion.
Otherwise Sybil would find out.
"Sam, what on earth are you doing?"
"I'm sitting down, dear."
"I can see that." She shot him a look that added in clear wife telepathy 'I can also see that you're sitting such that your ear is pressed firmly against that door.' He sighed, and got up, following her a little way down the hall.
"I just wanted to listen for a moment, see what they were up to-"
"Sam, he doesn't need you listening at every moment. He's not in any danger."
"I know, I know…"
Sybil shook her head.
"Even for you, Sam, this is unusually, well…extreme. Usually you just interview the poor girls for five minutes when they first arrive to check that they're not secretly assassins."
"No, dear. The price on our son's head is even higher than on Vetinari's." Lady Sybil paused, rearranging what she had been about to say.
"Really?"
"Yes. " Sam was grimly proud of that. Ha! No-one targeted his family. Well, not anymore^. Sybil blinked a few times.
"Well, then. No listening at doors!"
"Yes dear…" He watched her bustle off to feed the dragons. No listening. That would be a spanner in the works. Well. Not if he so happened to go and take a nice long bath. He wouldn't listen, but he couldn't help if he heard, now, could he?
"How was your day, dear?"
"It was good! We did fossils today. Look, here's one!"
"That is nice. Be sure to give it back."
"No, it's mine. I found it." In the usual way of child speech, this passed under the parental radar. It didn't quite make it under the Vimes Hyper Alert radar, though.
Found it? Where on earth would they find a fossil in a first floor room that had been cleaned only that morning? Without making the slightest sound?
Something was definitely going on.
*Being a policeman, Vimes was of course always suspicious. In this case, he was more suspicious than usual.
^ The last man to try was currently in the pleasant situation of trying to decide who's displeasure was the least pleasurable, Vimes' or Vetinari's. He was finding it an extremely, and surprisingly, close run thing.