When the doge arrives at San Maria Formosa, he is presented with two hats and two flagons of malmsey wine.

The parade is a wonderful excuse for a woman to send off her child and servants so she can be alone to receive a lover.

Just in case we were stupid, Franceschina added, "Valier's on the mainland on business and she'd probably felt lonely. When the maid came back, there she was, dead!"

"Had she received any messages that day?"

Franceschina's eyes grew even larger. "But yes, she had! However did you guess that, darling? No one knows what it said, except maybe the…" She dropped her voice to a whisper. "… Ten, you know?"

Rumor, which she happily passed on, said that there had been no signs of robbery or sexual violence. "But the boy's with his grandmother. Why don't you go and see her, dear? She'll be able to tell you much more."

Violetta tossed back her wine and said that in that case she must rush because she had to be home before sunset.

"The music salon at Ca' Grimini?" Franceschina chirped. "Will you be there, too? Oh, I am so looking forward to hearing that Milanese castrato, Whatsisname! They say he's an angel, absolutely divine!"

"I've heard him," Violetta said. "He sounds like a canary with severe constipation."

The weather was changing, just to remind us that it was still February, there were few people in sight, and Giorgio had taken shelter from the wind in a nearby loggia. He hastened to meet us.

"Another call to make," I said. "Close enough to walk to. We'll be as quick as we can."

Violetta and I paraded along the fondamenta to the calle Batello, down that about three houses, into a wide arched doorway-where stood Filiberto Vasco, the vizio, with his feet planted, his arms crossed, and a big smirk on his face.

"Go away, Alfeo," he said. "There's a good boy. No admittance."

As deputy to Missier Grande, the chief of police, Vasco would never post himself as a sentry on a chilly February corner. He thinks he is much too grand for that. He must have known that we were coming and had braved a few minutes' exposure just for the satisfaction of yanking my leash personally. He and I have been keeping score for several years, ever since a rich uncle bought him a job for which he is hopelessly inadequate and far too young. He loves to frighten people by flaunting his red cloak and silver belt badge, and his greatest ambition is to see me hanged between the columns on the Piazzetta.

Violetta and I had halted, of course.

"Says who?" I demanded, just to remind him that his authority came from much higher levels. His even larger smirk told me at once what was coming.

"Why, the Council of Ten, of course. Are you going to cause me trouble, Alfeo?"

"Why should I? You've never caused me any."

Violetta gave my arm a warning squeeze.

"I was instructed to tell you, boy, that you are to stop meddling in things that do not concern you. And that goes for that mountebank, Nostradamus, also. Tell him so. Now go away. And behave yourself, or it will go hard with you."

Since he and I attended the same fencing class, I knew I was a better fencer than he was. I admit I felt a momentary temptation to prove it with my rapier, right then and there, which would have been a wonderful treat, but one leading to a quick appointment with the headsman's ax. I regretfully decided to behave myself.

"What things, specifically, sbirro?"

His smile was intended to show that my insults were childish and he would settle them later. "Don't pretend to be stupider than you really are, Alfeo."

"Oh, you mean the Ludovici robbery?" I asked, in the hope that he might mention some cases I hadn't heard about yet.

"I mean any criminal matter at all. The magistrates enforce the law, not you. Go. I shan't warn you again."

There was nothing more to say. No one can argue with the Ten. They never answer questions, never explain, and there is no appeal from their decisions. I turned and walked away with Violetta and all the dignity I could muster, trying not to trip over the tail between my legs. Vasco stalked along behind us to see us off, whistling a cheerful tune.

Giorgio emerged from his shelter, noticing my fury but keeping his face diplomatically inscrutable. It wasn't until he'd rowed us well out of the vizio's hearing that he spoke.

"Where to?"

"Home!" I said. "We have been forbidden to meddle."

"Does that mean they've caught the devil?"

I always warn him when whatever I'm up to may be dangerous, so he knew who we were after.

"No." I glanced at Violetta and she nodded agreement. "It means they're protecting him."

After dropping off Violetta at the watergate of Number 96, I found the Maestro in his favorite chair, comparing two manuscript copies of a work by al-Kindi, the ninth-century philosopher who may be better known to you as Abu Yusuf Ya'qub ibn Is-haq ibn as-Sabbah ibn 'omran ibn Ismail al-Kindi. This was a bad sign, because it probably meant that he had been taking his mind off his sore hips and the Strangler both.

I reported.

"Can't fight the Ten," he growled. He detests arbitrary authority. It often provokes him into mulish defiance, which would be grievous folly in this case.

"And since Matteo must have told the sbirri about Honeycat," I said angrily, "and the Ten has records on everyone going back three hundred years, they must know who he is by now. He's a noble and they're protecting him!"

Nostradamus shrugged his narrow black-clad shoulders. "That depends how many people knew him by that name, but you are likely right. What matter if the Ten have forbidden us to investigate these murders? The state investigates crime, certainly, but it is every citizen's duty to prevent one. The Ten cannot object if we seek to prevent a murder that hasn't happened yet." He sighed. "Pass me my canes."

"If you are serious about preventing a murder," I said, "you could summon a much more effective assistant than me."

He scowled. "Not yet. Later, if we must."

That made sense, because the second law of demonology warns that a demon will always try to cheat, betray, and deceive, no matter how securely it is bound according to the first law. Prevention of a murder would be an altruistic purpose and therefore permitted by the third law, but summoning can never be truly safe.

"What do I do next, then?" I demanded. I was as restless as a bluebottle. Catching a killer is serious work at any time, but catching one who is going to kill is much more stressful.

"Nothing. Now it is my turn."

Massively relieved that he was going to bring his powers to bear on the problem, I gave the Maestro his canes and helped him rise. He crept across to the slate-topped table where he keeps the big crystal ball. I removed the red velvet cover, lit a candle, put chalk where he could reach it, and went to close the shutters on the blustery twilight outside. On the way back I grabbed a sheet of paper and a crayon from the desk.

"Anything else, master?"

"Yes. Go and feed. If I find anything you may be in for some strenuous activity this evening."

Of course the Strangler might not be planning anything at all. He might have done all the killing he wanted, or still be tracking his next victim, or be languishing in the palace cells. Or not. I found that the Maestro's warning had left me with surprisingly little appetite and a strong desire for company-going one-on-one against a murderer always makes me feel lonely. One possibility was Vettor Angeli, Giorgio's eldest, who lives elsewhere and is a gondolier in his own right. Vettor's a good lad with a cudgel or fists, but to take him out against a vicious three-time murderer would not be fair. More appealing was the thought of Fulgentio. A ducal equerry from a wealthy family does have some status-not enough to deter the Ten from taking action against him, because nobody has that security, not even the doge himself-but enough to make them prefer not to. He had been on his way to the palace that morning, so he ought to have finished his watch now and be home or on his way there.