Dee followed him into a quiet spot. "Yes?"
"Did Dozy go to the Scone Cave at the same time every day?"
"I believe so. It depended on his other duties."
"So he didn"t go in at the same time every day. Right. When does the guard change?"
"At each three o"clock."
"Did he go in before the guards change or afterwards?"
"That would depend on - "
"Oh dear. Don"t the guards write anything down?"
Dee stared at Vimes. "Are you saying he could have gone in twice in one day?"
"Very good. But I"m saying someone might have. A dwarf comes up in a boat alone, carrying a couple of candles. Would the guards take that much interest? And if another dwarf carrying a couple of candles came up an hour or so later, when the new guards were there... well, is there any real risk? Even if our faker was noticed he"d just have to mutter something about... oh, bad candles or something. Damp wicks. Anything."
Dee looked distant. "It"s still a great risk," he said at last.
"If our thief was keeping an eye on the guard changes, and knew where the real Dozy was, it"d be worth it, wouldn"t it? For the Scone?"
Dee shuddered and then nodded. "In the morning the guards will be closely questioned," he said.
"By me."
"Why?"
"Because I know what kind of questions get answers. We"ll set up an office here. We"ll find out the movements of everyone and talk to all the guards, Okay? Even the ones on the gates. We"ll find out who went in and out."
"You already think you know something."
"Let"s say some ideas are forming, shall we?"
"I will... see to matters."
Vimes straightened up and walked back to Lady Sybil, who stood like an island in a sea of dwarfs. She was talking animatedly to several of them who Vimes vaguely recognized as performers in the opera.
"What have you been up to, Sam?" she said.
"Politics, I"m afraid," said Vimes. "And trusting my instincts. Can you tell me who"s watching. us?"
"Oh, it"s that game, is it?" said Sybil. She smiled happily, and in the tones of someone chatting about inconsequential things said, "Practically everyone. But if I was handing out prizes I"d choose the rather sad lady in the little group just off to your left. She"s got fangs, Sam. And pearls, too. They don"t exactly accessorize."
"Can you see Wolfgang?"
"Er, no, not now you come to mention it. That"s odd. He was around a moment ago. Have you been upsetting people?"
"I think I may let people upset themselves," said Vimes.
"Good for you. You do that so well."
Vimes half turned, like someone just taking in the view. In amongst the human guests the dwarfs moved and clustered. Five or six would come together and talk animatedly. Then one would drift away and join another group. He might be replaced. And sometimes an entire group would spread out like the debris of an explosion, each member heading towards another group.
Vimes got the impression that there was a kind of structure behind all this, some slow, purposeful dance of information. Mineshaft meetings, he thought. Small groups, because there wouldn"t be room for more. And you don"t talk too loudly. And then when the group decides, every member is an ambassador for that decision. The word spreads out in circles. It"s like running a society on formal gossip.
It occurred to him that it was also a way in which two plus two could be debated and weighed and considered and discussed until it became four-and-a-bit, or possibly an egg.