“Yes, of course. That’s what comes of being a famous lawyer. Well, I’ll see you at two o’clock tomorrow afternoon.”

Mason and Della Street remained motionless, watching Mrs. Tump walk across the office with firm, competent steps. She made no effort to leave by the door through which she had entered, but walked directly to the door which opened from Mason’s private office into the outer corridor. She twisted the knurled knob which released the catch, and turned on the threshold to smile once more at them. “Don’t forget about that eleven o’clock appointment with Tidings, Mr. Mason,” she said, and pulled the door shut behind her.

When the latch had clicked into place, Mason trusted himself for the first time to look at Della Street.

“Ain’t we got fun!” she said.

Mason grinned. “I knew there was going to be a joker in the thing somewhere.”

Della, suddenly serious, tried to reassure him. “After all,” she said, “the coincidence may be just that and nothing more.”

“It may be,” he admitted, in a voice that showed his skepticism. “One chance in ten million if you want to make it mathematical.”

“Well,” she said, “I suppose that Mrs. Tump would hardly be the woman who holds the other part of that ten-thousand-dollar bill.”

“No,” Mason said, “but what do you want to bet that Byrl Gailord isn’t?”

“No takers,” she told him. “This is your personally conducted excursion into the realm of mysterious women and masked mistresses… Of course, if Byrl Gailord knew that Mrs. Tump was going to call on you and arrange for an appointment, she’d have been careful to keep you from hearing her voice… But I don’t see why all the secrecy.”