could possibly be within reach... ."
Baley said, "That's been made clear to me, and no matter how firm social customs are on Solaria, the point is not conclusive. May I explain?"
Gruer had returned to his dinner. "Of course."
"Murder rests on three legs," said Baley, "each equally important. They are motive, means, and opportunity. For a good case against any suspect, each of the three must be satisfied. Now I grant you that Mrs. Delmarre had the opportunity. As for the motive, I've heard of none."
Gruer shrugged. "We know of none." For a moment his eyes drifted to the silent Daneel.
"All right. The suspect has no known motive, but perhaps she's a pathological killer. We can let the matter ride for a while, and continue. She is in his laboratory with him and there's some reason why she wants to kill him. She waves some club or other heavy object threateningly. It takes him a while to realize that his wife really intends to hurt him. He shouts in dismay, 'You're going to kill me,' and so she does. He turns to run as the blow descends and it crushes the back of his head. Did a doctor examine the body, by the way?"
"Yes and no. The robots called a doctor to attend Mrs. Delmarre and, as a matter of course, he looked at the dead body, too."
"That wasn't mentioned in the report."
"It was scarcely pertinent. The man was dead. In fact, by the time the doctor could view the body, it had been stripped, washed, and prepared for cremation in the usual manner."
"In other words, the robots had destroyed evidence," said Baley, annoyed. Then: "Did you say he viewed the body? He didn't see it?"
"Great Space," said Gruer, "what a morbid notion. He viewed it, of course, from all necessary angles and at close focus, I'm sure. Doctors can't avoid seeing patients under some conditions, but I can't conceive of any reason why they should have to see corpses. Medicine is a dirty job, but even doctors draw the line somewhere."
"Well, the point is this. Did the doctor report anything about the nature of the wound that killed Dr. Delmarre?"
"I see what you're driving at.' You think that perhaps the wound was too severe to have been caused by a woman."
"A woman is weaker than a man, sir. And Mrs. Delmarre is a small woman."
"But quite athletic, Plainclothesman. Given a weapon of the proper type, gravity and leverage would do most of the work. Even not allowing for that, a woman in frenzy can do surprising things."
Baley shrugged. "You speak of a weapon. Where is it?"
Gruer shifted position. He held out his hand toward an empty glass and a robot entered the viewing field and filled it with a colorless fluid that might have been water.
Gruer held the filled glass momentarily, then put it down as though he had changed his mind about drinking. He said, "As is stated in the report, we have not been able to locate it."
"I know the report says that. I want to make absolutely certain of a few things. The weapon was searched for?"
"Thoroughly."
"By yourself?"
"By robots, but under my own viewing supervision at all times. We could locate nothing that might have been the weapon."
"That weakens the case against Mrs. Delmarre, doesn't it?"
"It does," said Gruer calmly. "It is one of several things about the case we don't understand. It is one reason why we have not acted against Mrs. Delmarre. It is one reason why I told you that the guilty party could not have committed the crime, either. Perhaps I should say that she apparently could not have committed the crime."
"Apparently?"
"She must have disposed of the weapon someway. So far, we have lacked the ingenuity to find it."
Baley said dourly, "Have you considered all possibilities?"
"I think so."
"I wonder. Let's see. A weapon has been used to crush a man's skull and it is not found at the scene of the crime. The only alternative is that it has been carried away. It could not have been carried away by Rikaine Delmarre. He was dead. Could it have been carried away by Gladia Delmarre?"
"It must have been," said Gruer.
"How? When the robots arrived, she was on the floor unconscious. Or she may have been feigning unconsciousness, but anyway she was there. How long a time between the murder and the arrival of the first robot?"
"That depends upon the exact time of the murder, which we don't know," said Gruer uneasily.
"I read the report,