"Got a key to the closet?" asked Mason.

"Yes, it's on my key ring."

"Let's lock this closet door and keep it locked while we've got the stuff in here," Mason said.

"Should we have it in the safe?"

"I don't think it's that important, particularly. But just the same, I'd like to have it under lock and key."

She crossed to the closet door and fitted the key to the lock, and snapped the bolt into position.

"You still haven't told me," she reminded him, "about how you underestimated Bradbury's intelligence."

"I had seen a girl walking away from the place. I figured she was mixed up in the murder in some way. I didn't know just how. I didn't care particularly, unless the girl happened to be Marjorie Clune. But I wanted to make certain about it, so I telephoned Bradbury."

"And told him Patton was murdered?"

"Yes, and asked him about Marjorie Clune. I knew that if it had been Marjorie Clune that was leaving the apartment, I had to work fast and keep ahead of the police."

"But there wasn't anything else you could have done, was there?" she asked. "You had to find out about it, and find out what Bradbury wanted done."

"I guess so."

"I thought," she said, "there was something wrong. He acted so absolutely startled when you telephoned to him. I don't know what there was in what you said, but it seemed to knock him for a loop. I thought he was going to drop the telephone. He started breathing through his mouth, and his eyes got so big I could have knocked them off with a stick."

"Well," Mason said, "that's the situation in a nutshell."

"And how does that get you in bad?" she asked.

"It gets me in bad," he said, "because I don't dare let the cops know that I was in that room. If I should tell them the truth now, they'd probably suspect me of the murder. I've got to stand by my story of the locked door. On the other hand, that locked door may figure in the case quite prominently. A whole lot more prominently than I want."

"Well," she said, "isn't that up to the police to figure out?"

"I'm not so certain," he said, "but I am certain that Bradbury is going to be a dangerous antagonist."

"An antagonist," she said, "why, he's a client. Why should he become an antagonist?"

"That," he said, "is just the point. That's where I overlooked my hand."

"How do you mean?"

"The girl who left the apartment was Marjorie Clune. She's mixed up in the thing some way. I don't know just how much. Bradbury is crazy about her. He's desperately in love with her, and he's served notice on me that if she gets mixed in it, he doesn't care whom he has to sacrifice. He's going to clear her at any cost."

Della Street squinted her eyes thoughtfully; then suddenly turned to her notebook.

"Did you," she said, "expect a message from a young woman who was to ring up and leave an address?"

"Yes," he said, "that's Marjorie Clune. She's going some place where I can talk with her. I haven't had a chance to talk with her yet and find out what happened. She had an audience all the time."

"Just before you came in," Della Street said, "a young woman's voice came over the telephone and said, 'Simply tell Mr. Mason I'm at the Bostwick Hotel, room 408, and to check that alibi. "

"That was all?" he asked.

"That was all."

"Check what alibi?"

"I don't know. I figured you would."

"There's only one person who has an alibi in this case," he said, "and I've checked it."

"Who's that?"

"That's Thelma Bell. She was out with a fellow named Sanborne, and I checked it before she got in communication with him."

"Perhaps that's the alibi she wanted you to check."

"I've already checked it."

He frowned thoughtfully at her; then shook his head slowly.

"That's the only thing it could mean," he said. "I'll check it again as soon as I've talked with Paul Drake. He'll be waiting around for me. He was to have met me out at Patton's apartment, but he got wise to what had happened, and kept back under cover."

"You want me to wait?" she asked.

"No," he said, "you go on home."

As she put on her hat and coat, and added touches of powder to her cheeks and lipstick to her lips, Perry Mason hooked his thumbs in the armholes of his vest, and started pacing up and down the floor.

"What is it, chief?" she asked, turning away from the mirror to watch him.

"I was thinking," he said, "about the blackjack."

"What about it?"

"When you can tell me," he said, "why a man should kill another man with a knife; then walk into another room and throw a blackjack in the corner, you'll have given me the solution of this whole case."

"Perhaps," she said, "it's one of those cases where a man planted evidence. He might have had a blackjack that had some one's fingerprints on it, some one that he wanted to implicate in the crime. The fingerprints might have been made months before he carried the blackjack, and then —"

"And then," he said, "he certainly would have killed the victim with the blackjack. There wasn't a mark on Patton's head. The thing that killed him was that knife thrust, and it killed him instantly. That blackjack had no more to do with the man's death than the revolver that's in the upper righthand drawer of my office desk."

"Why was it left there then?" she asked.

"That's what I want to know," he told her, and then suddenly laughed.

"You've got enough to puzzle your brains over without trying to turn detective."

She stood with her hand on the knob of the door, regarding him curiously.

"Chief," she said, "why don't you do like the other lawyers do?"

"You mean plant evidence, and suborn perjury?"

"No, I don't mean that. I mean, why don't you sit in your office and wait until the cases come to you? Let the police go out and work up the case, and then you walk into court and try and punch holes in it. Why do you always have to go out on the firing line and get mixed up in the case itself?"

He grinned at her.

"I'm hanged if I know," he said, "except that it's the way I'm built. That's all. Lots of times you can keep a jury from convicting a person because they haven't been proven guilty beyond a reasonable doubt. I don't like that kind of a verdict. I like to establish conclusively that a person is innocent. I like to play with facts. I have a mania for jumping into the middle of a situation, trying to size it up ahead of the police, and being the first one to guess what actually happened."

"And then to protect some one who is helpless," she said.

"Oh, sure," he said, "that's part of the game."

She smiled at him from the door.

"Good night," she said.

Perry Mason dialed the number of Paul Drake's office, and heard the voice of the detective saying cautiously, "Hello."

"Don't mention any names in case you're not alone. The coast is clear up here."

"I'll be in to see you in about ten minutes," Paul Drake said. "Can you wait?"

"Yes," Mason told him.

The lawyer dropped the receiver back into place, tilted back in his swivel chair and lit a cigarette. Then he took the end from his mouth and held the cigarette so that he could watch the smoke as it curled slowly upward. He sat entirely without motion, watching the curling smoke with eyes that seemed half dreamy. Not until the cigarette was more than half consumed did he nod his head slowly as though he had reached some decision; and then he returned the cigarette to his mouth. He smoked steadily until he had finished the cigarette, then pinched it out, dropped it in the ashtray, and looked at his watch.

It was at that moment that he heard a rattle on the knob of the door which opened into the corridor.

Perry Mason walked to the door, stood with his hand on the knob.