“Fireworks?” said Vimes.

Dr Cruces looked like a man grasping a floating log in a choppy sea.

“Yes. Fireworks. Yes. For Founder's Day. Unfortunately someone threw away a lighted match which ignited the box.” Dr Cruces suddenly smiled. “My dear Captain Vimes,” he said, clapping his hands, “much as I appreciate your concern, I really—”

“They were stored in that room over there?” said Vimes.

“Yes, but that's of no account—”

Vimes crossed to the hole in the wall and peered inside. A couple of Assassins glanced at Dr Cruces and reached nonchalantly towards various areas of their clothing. He shook his head. His caution might have had something to do with the way Carrot put his hand on the hilt of his sword, but it could also have been because Assassins did have a certain code, after all. It was dishonourable to kill someone if you weren't being paid.

“It seems to be some kind of… museum,” said Vimes. “Guild memorabilia, that sort of thing?”

“Yes, exactly. Odd and ends. You know how they mount up over the years.”

“Oh. Well, that all seems in order,” said Vimes. “Sorry to have troubled you, doctor. I will be going. I hope I have not inconvenienced you in any way.”

“Of course not! Glad to have been able to put your mind at rest.”

They were ushered gently yet firmly towards the gateway.

“I should clean up this glass,” said Captain Vimes, glancing at the debris again. “Someone could hurt themselves, all this glass lying around. Wouldn't like to see one of your people get hurt.”

“We shall be doing it right this minute, captain,” said Dr Cruces.

“Good. Good. Thank you very much.” Captain Vimes paused at the doorway, and then thumped the palm of his hand on his forehead. “Sorry, excuse me—mind like a sieve these days—what was it you said was stolen?”

Not a muscle, not a sinew moved on Dr Cruces' face.

“I didn't say anything was stolen, Captain Vimes.”

Vimes gaped at him for a moment.

“Right! Sorry! Of course, you didn't… Apologies… Work getting on top of me, I expect. I'll be going, then.”

The door slammed in his face.

“Right,” said Vimes.

“Captain, why—?” Carrot began. Vimes held up a hand.

“That wraps it up, then,” he said, slightly louder than necessary. “Nothing to worry about. Let's get back to the Yard. Where's Lance-Constable Whatshername?”

“Here, captain,” said Angua, stepping out of the alley.

“Hiding, eh? And what's that?”

“Woof woof whine whine.”

“It's a little dog, captain.”

“Good grief.”

The clang of the big corroded Inhumation Bell echoed through the Assassins' Guild. Black-clad figures came running from all directions, pushing and shoving in their haste to get to the courtyard.

The Guild council, assembled hurriedly outside Dr Cruces' office. His deputy, Mr Downey, knocked tentatively at the door.

“Come.”

The council filed in.

Cruces' office was the biggest room in the building. It always seemed wrong to visitors that the Assassins' Guild had such light, airy, well-designed premises, more like the premises of a gentlemen's club than a building where death was plotted on a daily basis.

Cheery sporting prints lined the walls, although the quarry was not, when you looked closely, stags or foxes. There were also group etchings—and, more recently, new-fangled iconographs—of the Guild, rows of smiling faces on black-clad bodies and the youngest members sitting cross-legged in front, one of them making a face.7

Down one side of the room was the big mahogany table where the elders of the Guild sat in weekly session. The other side of the room held Cruces' private library, and a small workbench. Above the bench was an apothecary cabinet, made up of hundreds of little drawers. The names on the drawer labels were in Assassins' code, but visitors from outside the Guild were generally sufficiently unnerved not to accept a drink.

Four pillars of black granite held up the ceiling. They had been carved with the names of noted Assassins from history. Cruces had his desk foursquare between them. He was standing behind it, his expression almost as wooden as the desk.

“I want a roll-call,” he snapped. “Has anyone left the Guild?”

“No, sir.”

“How can you be so sure?”

“The guards on the roofs in Filigree Street say no-one came in or went out, sir.”

“And who's watching them?”

“They're watching one another, sir.”

“Very well. Listen carefully. I want the mess cleaned up. If anyone needs to go outside the building, I want everyone watched. And then the Guild is going to be searched from top to bottom, do you understand?”

“What for, doctor?” said a junior lecturer in poisons.

“For… anything that is hidden. If you find anything and you don't know what it is, send for a council member immediately. And don't touch it.”

“But doctor, all sorts of things are hidden—”

“This will be different, do you understand?”

“No, sir.”

“Good. And no-one is to speak to the wretched Watch about this. You, boy… bring me my hat.” Dr Cruces sighed. “I suppose I shall have to go and tell the Patrician.”

“Hard luck, sir.”

The captain didn't say anything until they were crossing the Brass Bridge.

“Now then, Corporal Carrot,” he said, “you know how I've always told you how observation is important?”

“Yes, captain. I have always paid careful attention to your remarks on the subject.”

“So what did you observe?”

“Someone'd smashed a mirror. Everyone knows Assassins like mirrors. But if it was a museum, why was there a mirror there?”

“Please, sir?”

“Who said that?”

“Down here, sir. Lance-Constable Cuddy.”

“Oh, yes. Yes?”

“I know a bit about fireworks, sir. There's a smell you get after fireworks. Didn't smell it, sir. Smelled something else.”

“Well… smelled, Cuddy.”

“And there were bits of burned rope and pulleys.”

“I smelled dragon,” said Vimes.

“Sure, captain?”

“Trust me.” Vimes grimaced. If you spent any time in Lady Ramkin's company, you soon found out what dragons smelled like. If something put its head in your lap while you were dining, you said nothing, you just kept passing it titbits and hoped like hell it didn't hiccup.

“There was a glass case in that room,” he said. “It was smashed open. Hah! Something was stolen. There was a bit of card in the dust, but someone must have pinched it while old Cruces was talking to me. I'd give a hundred dollars to know what it said.”

“Why, captain?” said Corporal Carrot.

“Because that bastard Cruces doesn't want me to know.”

“I know what could have blown the hole open,” said Angua.

“What?”

“An exploding dragon.”

They walked in stunned silence.

“That could do it, sir,” said Carrot loyally. “The little devils go bang at the drop of a helmet.”

“Dragon,” muttered Vimes. “What makes you think it was a dragon, Lance-Constable Angua?”

Angua hesitated. “Because a dog told me” was not, she judged, a career-advancing thing to say at this point.

“Woman's intuition?” she suggested.

“I suppose,” said Vimes, “you wouldn't hazard an intuitive guess as to what was stolen?”

Angua shrugged. Carrot noticed how interestingly her chest moved.

“Something the Assassins wanted to keep where they could look at it?” she said.

“Oh, yes,” said Vimes. “I suppose next you'll tell me this dog saw it all?”

“Woof?”