“Well, then let’s suppose she went out on something fast, something which couldn’t wait.”

“What are you getting at, Paul?”

“Just this,” Drake said. “We weren’t where we were immediately available. Remember, we were going over to Marian Whiting’s. Della wouldn’t have called you there unless it had been a major emergency, because she knew you were going to try to shake Marian down for some information.”

“Go ahead,” Mason said. “Get to the answer. Never mind the preliminaries.”

“Remember,” Drake said, “just before we went over there, this table steward of yours had brought in a piece of blue silk. We’d cut it up into three pieces and—”

Mason nodded, fished the segment of blue silk out of his vest pocket and said, “Yes, you mentioned that before. Do you think she may have located that blue silk dress?”

Drake said, “Suppose she had? She’d have gone out to make sure, if she’d been in doubt. All right, now suppose while she was making sure, she tipped her hand, and someone did something about it.”

“That wouldn’t have happened,” Mason said. “It’s too unlikely.”

“Don’t kid yourself it’s unlikely,” Drake told him. “Let’s figure about that dress, Perry. That dress was on a cleat on the outside of the rail.” Mason nodded.

“And with the sea that was running, no one would have been climbing around on the outside of the rail.”