She smiled, and shook her head. “I knew you’d be working, and that if someone didn’t rescue you, you’d be pacing the floor until two or three o’clock in the morning. What’s Paul Drake found out?”

She picked up the sheets of flimsy, placed them together, and anchored everything in place with a paper-weight. “Come on, Chief.”

But he didn’t really answer her question until after he had relaxed in one of the booths in their favorite restaurant. He pushed back the plates containing the wreckage of a thick steak, and poured more coffee, then said, “Drake hasn’t found out much—just background.”

“What, for instance?”

Mason said wearily, “It’s the same old seven and six. The wife, Marline Austin Clements, apparently was swept off her feet by the sheer power of Carver Clements’s determination to get her. She overlooked the fact that after he had her safely listed as one of his legal chattels, he used that same acquisitive, aggressive tenacity of purpose to get other things he wanted. Marline was left pretty much alone.”

“And so?” Della asked.

“And so,” Mason said, “in the course of time, Carver Clements turned to other interests. Hang it, Della, we have one thing to work on, only one thing—the fact that Clements had no key on his body.

“You remember the four people who met us in the corridor. They had to get in that apartment house some way. Remember the outer door was locked. Any of the tenants could release the latch by pressing the button of an electric release. But if the tenant of some apartment didn’t press the release button, it was necessary to have a key in order to get in.

“Now, then, those four people got in. How? Regardless of what they say now, one of them must have had a key.”

“The missing key?” Della asked.

“That’s what we have to find out.”

“What story did they give the police?”

“I don’t know. The police have them sewed up tight. I’ve got to get one of them on the stand and cross-examine him. Then we’ll at least have something to go on.”

“So we have to try for an immediate hearing and then go it blind?”

“That’s about the size of it.”

“Was that key in Fay Allison’s purse Clements’s missing key?”

“It could have been. If so, either Fay was playing house or the key was planted. In that case, when was it planted, how, and by whom? I’m inclined to think Clements’s key must have been on his body at the time he was murdered. It wasn’t there when the police arrived. That’s the one really significant clue we have to work on.”

Della Street shook her head. “It’s too deep for me, but I guess you’re going to have to wade into it.”

Mason lit a cigarette. “Ordinarily I’d spar for time, but in this case I’m afraid time is our enemy, Della. We’re going to have to walk into court with all the assurance in the world and pull a very large rabbit out of a very small hat.”