Thissell explained. "It concerns the body which you referred to me this morning. I'm communicating with my superiors about it."

Rolver raised his head and listened to the sound of the incoming message. "You seem to be getting an answer. I'd better attend to it."

"Why bother?" asked Thissell. "Your slave seems efficient."

"It's my job," declared Rolver. "I'm responsible for the accurate transmission and receipt of all spacegrams."

"I'll come with you," said Thissell. "I've always wanted to watch the operation of the equipment."

"I'm afraid that's irregular," said Rolver. He went to the door which led into the inner compartment. "I'll have your message in a moment."

Thissell protested, but Rolver ignored him and went into the inner office.

Five minutes later he reappeared, carrying a small yellow envelope. "Not too good news," he announced with unconvincing commiseration.

Thissell glumly opened the envelope. The message read:

Thissell put the message in his pocket. "Incidentally, may I inquire the color of your hair?"

Rolver played a surprised little trill on his . "I'm quite blond. Why do you ask?"

"Mere curiosity."

Rolver played another run on his . "Now I understand. My dear fellow, what a suspicious nature you have! Look!" He turned and parted the folds of his mask at the nape of his neck. Thissell saw that Rolver was blond indeed.

"Are you reassured?" asked Rolver jocularly.

"Oh, indeed," said Thissell. "Incidentally, have you another mask you could lend me? I'm sick of this Moon Moth."

"I'm afraid not," said Rolver. "But you need merely go into a mask-maker's shop and make a selection."

"Yes, of course," said Thissell. He took his leave of Rolver and returned along the trail to Fan. Passing Welibus's office, he hesitated, then turned in. Today Welibus wore a dazzling confection of green glass prisms and silver beads, a mask Thissell had never seen before.

Welibus greeted him cautiously to the accompaniment of a . "Good morning, Ser Moon Moth."

"I won't take too much of your time," said Thissell, "but I have a rather personal question to put to you. What color is your hair?"

Welibus hesitated a fraction of a second, then turned his back, lifted the flap of his mask. Thissell saw heavy black ringlets. "Does that answer your question?" inquired Welibus.

"Completely," said Thissell. He crossed the esplanade, went out on the dock to Kershaul's houseboat. Kershaul greeted him without enthusiasm, and invited him aboard with a resigned wave of the hand.

"A question I'd like to ask," said Thissell; "What color is your hair?"

Kershaul laughed woefully. "What little remains is black. Why do you ask?"

"Curiosity."

"Come, come," said Kershaul with an unaccustomed bluffness. "There's more to it than that."

Thissell, feeling the need of counsel, admitted as much. "Here's the situation. A dead out-worlder was found in the harbor this morning. His hair was brown. I'm not entirely certain, but the chances are -- let me see, yes, two out of three that Angmark's hair is black."

Kershaul pulled at the Cave-Owl's goatee. "How do you arrive at that probability?"

"The information came to me through Rolver's hands. He has blond hair. If Angmark has assumed Rolver's identity, he would naturally alter the information which came to me this morning. Both you and Welibus admit to black hair."

"Hm," said Kershaul. "Let me see if I follow your line of reasoning. You feel that Haxo Angmark has killed either Rolver, Welibus or myself and assumed the dead man's identity. Right?"

Thissell looked at him in surprise. "You yourself emphasized that Angmark could not set up another out-world establishment without revealing himself! Don't you remember?"

"Oh, certainly. To continue, Rolver delivered a message to you stating that Angmark was dark, and announced himself to be blond."

"Yes. Can you verify this? I mean, for the old Rolver."

"No," said Kershaul sadly. "I've seen neither Rolver nor Welibus without their masks."

"If Rolver is not Angmark," Thissell mused, "if Angmark indeed has black hair, then both you and Welibus come under suspicion."

"Very interesting," said Kershaul. He examined Thissell warily. "For that matter, you yourself might be Angmark. What color is your hair?"

"Brown," said Thissell curtly. He lifted the gray fur of the Moon Moth mask at the back of his head.

"But you might be deceiving me as to the text of the message," Kershaul put forward.

"I'm not," said Thissell wearily. "You can check with Rolver if you care to."

Kershaul shook his head. "Unnecessary. I believe you. But another matter: what of voices? You've heard all of us before and after Angmark arrived. Isn't there some indication there?"

"No. I'm so alert for any evidence of change that you all sound rather different. And the masks muffle your voices."

Kershaul tugged the goatee. "I don't see any immediate solution to the problem." He chuckled. "In any event, need there be? Before Angmark's advent, there were Rolver, Welibus, Kershaul and Thissell. Now -- for all practical purposes -- there are still Rolver, Welibus, Kershaul and Thissell. Who is to say that the new member may not be an improvement upon the old?"

"An interesting thought," agreed Thissell, "but it so happens that I have a personal interest in identifying Angmark. My career is at stake."

"I see," murmured Kershaul. "The situation then becomes an issue between yourself and Angmark."

"You won't help me?"

"Not actively. I've become pervaded with Sirenese individualism. I think you'll find that Rolver and Welibus will respond similarly." He sighed. "All of us have been here too long."