Lord Darcy laughed. “Far from it. My Lord Marquis would like me to do just that, but I shan’t oblige him. The case is interesting, of course, but my duty lies in Normandy. Just among the three of us — and I ask you to let it go no further until after tomorrow — I intend to get Master Sean out by presenting my cousin de London with a dilemma. For that purpose, I have gathered enough facts to force him to release Master Sean. Then the two of us shall return to Normandy.”

Mary de Cumberland looked at him with an expression that was both hurt and astonished. “You’re returning and taking Master Sean with you? So soon? Shan’t he be permitted to finish Convention Week?”

“I’m afraid not,” Lord Darcy said. There was apology and contriteness in his manner and voice. “We have a murder of our own to solve, Sean and I. I can’t reveal details, and I admit that the case is neither as spectacular nor as… er… notorious as this one, but duty is duty. If the matter can be resolved quickly, of course, Master Sean may be back before the week is out.”

“But what about the paper he was to present?” the Duchess persisted.

“If it is at all possible,” Lord Darcy promised firmly, “I shall see that he gets back. If nothing else, I shall see to it that he gets back Saturday to deliver his paper. That, after all, is a part of his duty as a sorcerer.”

“And you’ll just hand the case right back to Lord Bontriomphe, eh?” asked Sir Thomas.

“I don’t need to hand it back,” said Lord Darcy with a chuckle, “since I did not accept it in the first place. It’s all his, and I wish him luck. He and the Marquis are perfectly capable of its solution, have no fear of that.”

“Without a forensic sorcerer to aid them?” Sir Thomas said.

“They’ll manage,” said Lord Darcy. “The late Sir James Zwinge was not the only capable forensic sorcerer in London. Besides, it is apparent that My Lord Marquis does not feel the need for a good forensic sorcerer. As soon as the second-best one was killed, he proceeded to lock up the best one. Hardly the act of a man who was desperate for first-class thaumaturgical advice.”

As the other two laughed quietly, Lord Darcy took a sip from his brandy goblet.

A door at the other end of the room opened.

“Good evening, Your Grace; good evening, gentlemen,” said a warm baritone voice. “I’m terribly sorry. Have I interrupted any thing?”

Lord Darcy, too, had turned to look. The newcomer was a handsome young man in crimson and gold evening dress whose distinctive features marked him as Mechicain. This, then, was Lord John Quetzal du Moqtessuma de Mechicoe.

“Not at all, my lord,” said the Duchess, “we have been expecting you. Come in and permit me to introduce our new guest.”

The introductions were made in due form, and Lord John Quetzal’s heavy-lidded eyes brightened as Lord Darcy’s name was spoken.

“It’s a very great pleasure to meet you, my lord,” he said, “though, of course, I deplore the circumstances that bring you here. I do not for a moment believe Master Sean guilty of this terrible crime.”

“Thank you, my lord,” Lord Darcy replied. “And I thank you for Master Sean, too.” Then he added smoothly, “I did not realize that Master Sean’s guilelessness was so transparently obvious that it would be utterly convincing upon such short acquaintance.”

The Mechicain looked rather self-conscious. “Well, it’s not exactly that. Transparent? No, I shouldn’t say that Master Sean is at all transparent. It’s… er—” He hesitated in momentary confusion.

“My Lord John Quetzal’s modesty does him credit,” the Duchess cut in gently. “His is a Talent rare even among sorcerers. He is a witch-smeller.”

“Indeed?” Lord Darcy looked at the young man with increased interest. “I confess that I have never met a sorcerer with that ability before. You can detect, then, the presence of a practitioner of black magic, even at a distance?”

Lord John Quetzal nodded. “Yes, my lord.” He seemed embarrassed, like an adolescent lad who has just been told he is very handsome by a beautiful woman.

Sir Thomas chuckled. “Naturally, Lord Darcy, he would know immediately that Master Sean does not dabble in black magic. To a witch-smeller, that would be instantly apparent.” He turned his smile toward Lord John Quetzal. “When we have some free time together, I should like to discuss theory with you and see how it actually squares with practical results.”

“That… that would be an honor and a pleasure, Sir Thomas,” said the young nobleman. There was an awestruck note in his voice. “But… but I’m very weak in symbological theory. My math isn’t exactly my strong point.”

Sir Thomas laughed. “Don’t worry, my lord; I promise not to smother you in analogy equations. Good Heavens, that’s work! When I am away from my library, I do everything I can to avoid any heavy thinking.”

That, Lord Darcy knew, was not true; Sir Thomas was merely putting the young man at ease. Sir Thomas Leseaux, in spite of his degree of Doctor of Thaumaturgy, was not a practicing sorcerer. He did not possess the Talent to any marked degree. He was a theoretical thaumaturgist who worked with the higher and more esoteric forms of the subjective algebrae, leaving it to others to test his theories in practice. His brilliant mind was capable of grasping symbological relationships that an ordinary sorcerer could only dimly perceive. There were very few Th.D.’s who could follow his abstruse and complex symbolic analogies through to their final conclusions; most Masters of the Art bogged down hopelessly after the first few similarities. Sir Thomas had not been so lacking in awareness as to suppose a mere Journeyman could follow his mathematics. On the other hand, he immensely enjoyed discussing the Art with practicing magicians.

“May I ask you a question, my lord?” Lord Darcy asked thoughtfully. “Even though I am not officially involved in the investigation of the murder of Sir James Zwinge, a man in my profession has a certain natural curiosity. I should like to ask you what might be considered a professional question, and” — he smiled — “if you like you may send me a bill for services rendered.”

Lord John Quetzal returned the smile. “If the question requires that I invoke a spell, I shall most certainly bill you — at the usual Journeyman’s rates, of course. To do otherwise would impair my standing in the Guild. But if you merely want a professional opinion, I am at your service.”

“Then I shall leave the matter in your hands,” said Lord Darcy. “The question is: Have you detected the presence of a black magician amongst the members of the Convention?”

There was a sudden silence, as if time itself were suspended for a moment. Both Sir Thomas and the Duchess seemed to be holding their breaths, awaiting the young Mechicain nobleman’s answer.

But from Lord John Quetzal there was only a moment of hesitancy. When he spoke, his voice was firm.

“My lord, it is my ambition to study forensic sorcery under the tutelage of a Master. I have, as a matter of course, studied both law enforcement and criminal detection. May I counter your question with one of my own?”

“Certainly,” said Lord Darcy.

Lord John Quetzal compressed his lips for a moment in thought before continuing. “Let us suppose that you personally knew, through the exercise of your own abilities, that a certain man was a criminal — that he had committed a particular crime. But let us further assume that, aside from your own personal knowledge, there was not one shred of proof whatever of the fact. My counter-question is: Would you denounce the man?”

“No,” said Lord Darcy without hesitation. “Your point is well taken. It is nugatory to accuse a man without proof. But a word to the investigating officials, merely to give them a lead so they can discover proof if it exists, is certainly not a public accusation.”

“Perhaps not,” said the young sorcerer slowly. “I shall certainly take your words under advisement. But at the moment I feel that my unsupported word alone is not sufficient evidence even for that.”