"One little thing," corrected Mandel quietly. "Recovery."

"What does that mean?" asked Ryger sharply.

Mandel said, "When did you three see him last?"

Talliaferro spoke. "Last evening. It turned out to be a reunion. We all met for the first time in ten years. It wasn't a pleasant meeting, I'm sorry to say. Villiers felt he had cause for anger with us, and he was angry."

"That was-when?"

"About nine, the first time."

"The first time?"

"We saw him again later in the evening."

Kaunas looked troubled. "He had left angrily. We couldn't leave it at that. We had to try. It wasn't as if we hadn't all been friends at one time. So we went to his room and-"

Mandel pounced on that. "You were all in his room?"

"Yes," said Kaunas, surprised.

"About when?"

"Eleven, I think." He looked at the others. Talliaferro nodded.

"And how long did you stay?"

"Two minutes," put in Ryger. "He ordered us out as though we were after his paper." He paused as though expecting Mandel to ask what paper, but Mandel said nothing. He went on. "I think he kept it under his pillow. At least he lay across the pillow as he yelled at us to leave."

"He may have been dying then," said Kaunas, in a sick whisper.

"Not then," said Mandel shortly. "So you probably all left fingerprints."

"Probably," said Talliaferro. He was losing some of his automatic respect

for Mandel and a sense of impatience was returning. It was four in the morning, Mandel or no. He said, "Now what's all this about?"

"Well, gentlemen," said Mandel, "there's more to Villiers' death than the fact of death. Villiers' paper, the only copy of it as far as I know, was stuffed into the cigarette flash-disposal unit and only scraps of it were left. I've never seen or read the paper, but I knew enough about the matter to be willing to swear in court if necessary that the remnants of unflashed paper in the disposal unit were of the paper he was planning to give at this Convention. -You seem doubtful, Dr. Ryger."

Ryger smiled sourly. "Doubtful that he was going to give it. If you want my opinion, sir, he was mad. For ten years he was a prisoner of Earth and he fantasied mass-transference as escape. It was all that kept him alive probably. He rigged up some sort of fraudulent demonstration. I don't say it was deliberate fraud. He was probably madly sincere, and sincerely mad. Last evening was the climax. He came to our rooms-he hated us for having escaped Earth-and triumphed over us. It was what he had lived for for ten years. It may have shocked him back to some form of sanity. He knew he couldn't actually give the paper; there was nothing to give. So he burnt it and his heart gave out. It is too bad."

Mandel listened to the Cerian astronomer, wearing a look of sharp disapproval. He said, "Very glib, Dr. Ryger, but quite wrong. I am not as easily fooled by fraudulent demonstrations as you may believe. Now according to the registration data, which I have been forced to check rather hastily, you three were his classmates at college. Is that right?"

They nodded.

"Are there any other classmates of yours present at the Convention?"

"No," said Kaunas. "We were the only four qualifying for a doctorate in astronomy that year. At least he would have qualified except-"

"Yes, I understand," said Mandel. "Well, then, in that case one of you three visited Villiers in his room one last time at midnight."

There was a short silence. Then Ryger said coldly, "Not I." Kaunas, eyes wide, shook his head.

Talliaferro said, "What are you implying?"

"One of you came to him at midnight and insisted on seeing his paper. I don't know the motive. Conceivably, it was with the deliberate intention of forcing him into heart failure. When Villiers collapsed, the criminal, if I may call him so, was ready. He snatched the paper which, I might add, probably was kept under his pillow, and scanned it. Then he destroyed the paper itself in the flash-disposal, but he was in a hurry and destruction wasn't complete."

Ryger interrupted. "How do you know all this? Were you a witness?"

"Almost," said Mandel. "Villiers was not quite dead at the moment of his first collapse. When the criminal left, he managed to reach the phone and call my room. He choked out a few phrases, enough to outline what had

occurred. Unfortunately I was not in my room; a late conference kept me away. However, my recording attachment taped it. I always play the recording tape back whenever I return to my room or office. Bureaucratic habit. I called back. He was dead."

"Well, then," said Ryger, "who did he say did it?"

"He didn't. Or if he did, it was unintelligible. But one word rang out clearly. It was 'classmate.' "

Talliaferro detached his scanner from its place in his inner jacket pocket and held it out toward Mandel. Quietly he said, "If you would like to develop the film in my scanner, you are welcome to do so. You will not find Villiers' paper there."

At once, Kaunas did the same, and Ryger, with a scowl, joined.

Mandel took all three scanners and said dryly, "Presumably, whichever one of you has done this has already disposed of the piece of exposed film with the paper on it. However-"

Talliaferro raised his eyebrows. "You may search my person or my room."

But Ryger was still scowling, "Now wait a minute, wait one bloody minute. Are you the police?"

Mandel stared at him. "Do you want the police? Do you want a scandal and a murder charge? Do you want the Convention disrupted and the System press to make a holiday out of astronomy and astronomers? Villiers' death might well have been accidental. He did have a bad heart. Whichever one of you was there may well have acted on impulse. It may not have been a premeditated crime. If whoever it is will return the negative, we can avoid a great deal of trouble."

"Even for the criminal?" asked Talliaferro.

Mandel shrugged. "There may be trouble for him. I will not promise immunity. But whatever the trouble, it won't be public disgrace and life imprisonment, as it might be if the police are called in."

Silence.

Mandel said, "It is one of you three."

Silence.

Mandel went on, "I think I can see the original reasoning of the guilty person. The paper would be destroyed. Only we four knew of the mass-transference and only I had ever seen a demonstration. Moreover you had only his word, a madman's word perhaps, that I had seen it. With Villiers dead of heart failure and the paper gone, it would be easy to believe Dr. Ryger's theory that there was no mass-transference and never had been. A year or two might pass and our criminal, in possession of the mass-transference data, could reveal it little by little, rig experiments, publish careful papers, and end as the apparent discoverer with all that would imply in terms of money and renown. Even his own classmates would suspect nothing. At most they would believe that the long-past affair with Villiers had inspired him to begin investigations in the field. No more."

Mandel looked sharply from one face to another. "But none of that will work now. Any of the three of you who comes through with mass-transference is proclaiming himself the criminal. I've seen the demonstration; I know it is legitimate; I know that one of you possesses a record of the paper. The information is therefore useless to you. Give it up then."

Silence.

Mandel walked to the door and turned again, "I'd appreciate it if you would stay here till I return. I won't be long. I hope the guilty one will use the interval to consider. If he's afraid a confession will lose him his job, let him remember that a session with the police may lose him his liberty and cost him the Psychic Probe." He hefted the three scanners, looked grim and somewhat in need of sleep. "I'll develop these."