"Did Alex complain about that?" asked Trumbull with sudden interest.

"No, but then he's no great lover, either. Listen, he's been a widower for three years now and I'm willing to swear he has no girl of any kind. No boy, either, before you start talking about that."

Rubin said, "Hold it, you still don't know what the argument was really about. You said it was something that happened at work. Did he actually tell you what it was and you've just forgotten; or did he never tell you?"

"He didn't go into detail, and I didn't ask. It wasn't my business."

"All right," said Rubin, "how about this? It was an argument about something big at work. Maybe Alex had stolen fifty thousand dollars and Marge was sore about it, and that was the argument. Or Marge had made him steal it and he was getting cold feet about it and that was the argument. And maybe the fifty thousand was in the house and someone knew about it and that someone killed her and took it and Alex doesn't dare mention it."

"What someone?" demanded Gonzalo. "What theft? Alex wasn't that kind of guy."

"Famous last words," intoned Drake. "Well, he wasn't. And if he had done it, the firm he worked for wouldn't have kept quiet. No chance."

Trumbull said, "How about the kind of in-fighting that goes on in apartment houses? You know, feuds between tenants. Was there someone who hated her and finally let her have it?"

"Hell, if there were anything that serious, I'd know about it. Marge never kept things like that quiet."

Drake said, "Could it be suicide? After all, her husband had just walked out on her. Maybe he said he was never coming back and she was in despair. In a fit of irrational depression, she killed herself."

"It was a knife from the kitchen," said Gonzalo. "There's that. But Marge isn't the suicidal type. She might kill someone eke, but not herself. Besides, why would there be that struggle and the scream if she had killed herself?"

Drake said, "In the first place, things might have been knocked about during the argument with her husband. In the second place, she might have faked a murder to get her husband into trouble. Vengeance is mine, saith the aggrieved wife."

"Oh, come on," said Gonzalo contemptuously. "Marge wouldn't do something like that in a million years."

"You know," said Drake, "you don't really know all that much about another person-even if she's a twin."

"Well, you won't get me to believe it."

Trumbull said, "I don't know why we're wasting our time. Why don't we ask the expert?… Henry?"

Henry, whose face mirrored only polite interest, said, "Yes, Mr. Trumbull?"

"How about telling us all about it? Who killed Mr. Gonzalo's sister?"

Henry's eyebrows lifted slightly. "I do not represent myself to be an expert, Mr. Trumbull, but I must say that all the suggestions made by the gentlemen at the table, including yours, are unlikely in the extreme. I myself think that the police are perfectly correct and that if, in this case, the husband did not do it, then housebreakers did. And these days, one must assume that those housebreakers were drug addicts desperate for money or for something they can convert into money."

"You disappoint me, Henry," said Trumbull.

Henry smiled gently.

"Well, then," said Halsted, "I guess we'd better adjourn after we settle who hosts next time, and I suppose we'd better go back to having guests. This scheme of mine didn't work out so well."

"Sorry I couldn't make it better, folks," said Gonzalo.

"I didn't mean it that way, Mario," said Halsted hastily-

"I know. Well, let's forget it."

They were leaving, with Mario Gonzalo bringing up the rear. A light tap at his shoulder caused Gonzalo to turn.

Henry said, "Mr. Gonzalo, could I see you privately, without the others knowing? It's quite important."

Gonzalo stared a moment and said, "Okay, I'll go out, say my goodbyes, take a taxi, and have it bring me back." He was back in ten minutes.

"Is this something about my sister, Henry?"

"I'm afraid so, sir. I thought I had better talk to you, privately."

"All right. Let's go back into the chamber. It's empty now."

"Better not, sir. Anything said in that room can't be repeated outside and I do not wish to talk in confidence. I don't mind finding myself hushed up about average run-of-the-mill misdeeds, but murder is another thing altogether. There's a corner here that we can use."

They went together to the indicated place. It was late and the restaurant was virtually empty.

Henry said, in a low voice, "I listened to the account and I would like your permission to repeat some of it just to make sure I have it right."

"Sure, go ahead."

"As I understand it, on a Saturday toward the end of April, you felt uneasy and went to bed before the eleven-o'clock news."

"Yes, just before eleven o'clock."

"And you didn't hear the news."

"Not even the opening headlines."

"And that night, even though you didn't sleep, you didn't get out of bed. You didn't go to the bathroom or the kitchen."

"No, I didn't."

"And then you woke up at exactly the same time you always do."

"That's right."

"Well, now, Mr. Gonzalo, that is what disturbs me. A person who wakes up every morning at exactly the same time, thanks to some sort of biological clock inside him, wakes up at the wrong time twice a year."

"What?"

"Twice a year, sir, in this state, ordinary clocks are shifted, once when Daylight Saving Time starts, and once when it ends, but biological time doesn't change suddenly. Mr. Gonzalo, on the last Sunday in April, Daylight Saving Time starts. At one a.m. Sunday morning the clocks are shifted to two a.m. If you had listened to the eleven-o'clock news you would have been reminded to do that. But you wound you clock before eleven P.M. and you said nothing about adjusting it. Then you went to bed and never touched it during the night. When you woke at eight a.m., the clock should have said nine a.m. Am I right?"

"Good Lord," said Gonzalo.

"You left after the police called and you didn't come back for days. When you came back the clock was stopped, of course. You had no way of knowing that it was an hour slow when it had stopped. You set it to the correct time and never knew the difference."

"I never thought of that, but you're perfectly right."

"The police should have thought of that, but it's so easy these days to dismiss run-of-the-mill crimes of violence as the work of addicts. You gave your brother-in-law his alibi and they followed the line of least resistance."

"You mean he-"

"It's possible, sir. They fought, and he killed her at nine a.m. as the statements of the neighbors indicated. I doubt that it was premeditated. Then, in desperation, he thought of you-and rather clever of him it was. He called you and asked you what time it was. You said eight-oh-nine and he knew you hadn't altered the clock and rushed over to your place. If you had said nine-oh-nine, he would have tried to get out of town."

"But, Henry, why should he have done it?"

"It's hard to tell with married couples, sir. Your sister may have had too high standards. You said she disapproved of your way of life, for instance, and probably made that very plain, plain enough to cause you not to like her very well. Now she must have disapproved of her husband's way of life, as it was before she had married him. He was a drifter, you said. She made of him a respectable, hard-working employee and he may not have liked it. After he finally exploded and killed her, he became a drifter again. You think this is so out of despair; he may have nothing more than the feeling of relief."

"Well… What do we do?"

"I don't know, sir. It would be a hard thing to prove. Could you really remember, after three years, that you didn't adjust the clock? A cross-examining attorney would tear you apart. On the other hand, your brother-in-law might break down if faced with it. You'll have to consider whether you wish to go to the police, sir."