At the Palace Hotel Sunday morning where I went to pick up Worth before we should call for little Miss Wallace, he met me in high spirits and with an enthusiasm that demanded immediate physical action.

"Heh," I said, "you look fine. Must have slept well."

"Make it rested, and I'll go you," he came back cheerfully.

He'd already been out, going down to the Grant Avenue corner for an assortment of Bay cities papers not to be had at the hotel news-stands, so that he could see whether our canny announcement of Clayte's fifteen thousand dollar defalcation had received discreet attention from the Associated Press.

For my part, our agency had been able to get hold of three women who had seen Clayte and remembered the event; Mrs. Griggsby; a stenographer at the bank; and the woman who sold newspapers at the St. Dunstan corner. Miss Wallace's suggestion had proven itself, for these three agreed with fair exactness, and the description run in the late editions of the city papers was less vague than the others. It gave Clayte's eyes as a pale gray-blue, and his hair as dull brown, eliminating at least all brown-eyed men. Worth asserted warmly,

"That girl's going to be useful to us, Boyne." I couldn't well disagree with him, after using her hint. We were getting out of the elevator on the office floor when he looked at me, grinned boyishly, and added, "What would you say if I told you I was being shadowed?"

"That I thought it very likely," I nodded. "Also I might hazard a guess at whose money is paying for it."

He gave me a quick glance, but asked no questions. I could see he was enjoying his position, up to the hilt, considered the attentions of a trailer as one of its perquisites.

"Keep your eyes open and you'll spot him as we go out," he said as he left the key at the desk.

It was hardly necessary to keep my eyes open to see the lurking figure over beyond the easy-chairs, which started galvanically as we passed through the court, and a moment later came sidling after us. Little Pete had left my machine at the Market Street entrance—Worth was to drive me—and we wheeled away from a disappointed man racing for the taxi line around the corner.

"More power to his legs," Worth said.

"Oh, I don't know," I grunted as we cut into Montgomery, negotiated the corner onto Bush Street's clear way, striking a fair clip at once. "That end of him already works better than the other. How did you get wise?"

"Barbara Wallace telephoned me to look out for him," he smiled, and let my car out another notch once we'd passed the traffic cop at Kearny.

I myself had foreseen the possibility—but only as a possibility—that Dykeman would put a man on Worth's coat-tails, since I knew Dykeman and had been at that bank meeting; yet I had not regarded it as likely enough to warn Worth; and here was this girl phoning him to look out for a trailer. Was this some more of her deductive reasoning, or had Cummings dropped a hint?

She was waiting for us in front of the Haight Street boarding house that served her for a home, and we tucked her between us on the roadster's wide seat. At the St. Dunstan we found my man, left there since the hour of the alarm the day before, and everybody belonging to the management surly and glum. The clerk handed me Clayte's key across the morning papers spread out on his desk. Apartment houses dislike notoriety of this sort, and the St. Dunstan set up to be as rabidly respectable, as chemically pure as any in the city. Well, no use their blaming me; Clayte was their misfortune; they couldn't expect me to keep the matter out of print entirely.

The three of us crowded into the automatic elevator, and I pressed the seventh floor button. The girl's eyes shone under the wisp of veil twisted around a knowing little turban. She liked the taste of the adventure.

"That man came this way—with that suitcase," she breathed, "—maybe set it down right there when he pressed the button—just as Mr. Boyne did now!"

It was a fine morning; the shades had been left up, and Clayte's room when I opened the door was ablaze with sunlight.

"How delightful!" Barbara Wallace stopped on the threshold and looked about her. I expected the scientific investigating to begin; but no—she was all taken up with the beauty of sunlight and view.The seventh was the top floor. The St. Dunstan stood almost at the summit where Nob Hill slants obliquely to north and east, and Powell Street dizzies down the steep descent to North Beach and the Bay. The girl had run to a window, and was looking out toward the marvelous show of blue-green water and distant Berkeley hills.

"Will you open this window for me, please?" she asked. I stepped to her side, forestalling Worth who was eyeing the room's interior with curiosity.

"You'll notice the burglar-proof sash locks," I said as I manipulated this one. She gave only casual interest, her attention still on the view beyond. The steel latch, fastened to the upper sash, locked into the socket on the lower sash by a lever-catch. "See? I must pull out this little lever before I can push the hasp back with my thumb—so. Now the window may be shoved up," and I illustrated.

"Yes," she nodded; then, "Look at the wisps of fog around Tamalpais's top. Worth, come here and see the violet shadows of the clouds on the bay."

"North wind coming up," agreed Worth, stepping to the farther window.

"It's bringing in the fog," she said; then abruptly, giving me the first hint that little Miss Wallace considered herself on the job, "Will it not latch by itself if you jam it shut hard?"

"It will not." I illustrated with a bang. The latch still remained open. "I must close it by hand." I pushed the hasp into the keeper, and, snap—the lever shot back and it was fast.

"But a window like that couldn't be opened from outside, even without the locking lever," she remarked, gazing again toward the Marin shore.

"A man with the know—a burglar—can open the ordinary window latch in less than a minute," I told her. "With a jimmy pinched between the sash and the sill, a recurring pressure starts the latch back; nothing to hold it. This—unless he cuts the glass—is burglar-proof."

Worth, at her shoulder, now looked down the sheer descent which exaggerated the seven stories of the St. Dunstan; because of its crowning position on the hill and the intersection of streets, we looked over the roofs of the houses before us, far above their chimney tops. I caught his eye and grinned across the girl's head, suggesting,

"Besides, we weren't trying to find how some one could break into this room, but how they could break out. Even if the latches had not been locked, there wouldn't be an answer in these windows—unless Clayte could fly."

"Might have climbed from one window ledge to the next and so made his way to the fire-escape," Worth said, but I shook my head.

"He'd be seen from the windows by the tenants on six floors—and nobody saw him. Might as well take the elevator or the stairs—which he didn't."

But the girl wasn't listening to any of this. Her expression attentive, alert, she was passing her hand around the edge of the glass of either sash, as though she still dwelt on my suggestion of cutting the pane; and as we watched her, she murmured to herself,

"Yes, flying would be a good way." It made me laugh.And then she turned away from the windows and had no more interest in any of them, going with me all over the rest of the room with rather the air of a person who thought of renting it than a high-brow criminal investigator hunting clews.

"He lived here—years, you say?" I nodded. She slid her hand over the plush cushions of a morris chair, threw back the covers of an iron bed in one corner and felt of the mattress, then went and stood before the bare little dresser. "Why, the place expresses no more personality than a room in a transient hotel!"

"He hadn't any personality," I growled, and got the flicker of a smile from her eye.

"What about those library books he carried in the suitcase?" Worth came in with an echo from the bank meeting.

"Some more bunk," I said morosely. "So far we've not been able to locate him as a patron of any public or private library, and the hotel clerk's sure his mail never contained a correspondence course—in fact, neither here nor at the bank can any one remember his getting any mail. If he ever carried books in that suitcase as Knapp believed, it was several years back."

"Several years back," Miss Wallace repeated low.

"Myself, I've given up the idea of his studying. This crime doesn't look to me like any sudden temptation of a model bank clerk, spending his spare hours over correspondence courses. I rather expect to find him just plain crook."

"Oh, no," the girl objected. "It's too big and too well done to have been planned by a dull, commonplace crook.""Right you are," I agreed, with restored good humor. "A keen brain planned this, but not Clayte's. There had to be an instrument—and that was Clayte—also, likely, one or more to help in the getaway."

The getaway! That brought us back with a thump to the present moment. Our pretty girl had been all over the shop now, glanced into bathroom, closet and cupboard, noted abandoned hats, clothing and shoes, the electric plate where Clayte got his breakfast coffee and toast, asked without much interest where he ate his other meals, and nodded agreeingly when she found that he'd been only an occasional customer at the neighboring restaurants, never regular, apparently eating here and there down-town. She seemed to get something out of that; what I didn't know.

"You speak of this crime not being committed on impulse," she turned to me at length. "How long ahead should you say he planned it?"

"Or had it planned and prepared for him," I reminded her.

"Well, that, then," she conceded with slight impatience. "How long do you think it might have been planned or prepared for? Years?"

"Hardly that. Not more than a year probably. A gang like this wouldn't hold together on a proposition for many months."

The black brows over those clear, childlike eyes, puckered a bit. I saw she wasn't at all satisfied with what I had said.

"Made all the observations you want to, Bobs?" Worth asked.

"All here. I want to see the roof." She gave us rather a mechanical smile as she silently ticked her points off on her fingers, appealing to me with, "I'm depending upon you for such facts as I have been unable to observe for myself, so if you give me wrong facts—make mistakes—I'll make mistakes in deduction."

There was such confidence in her deductive abilities that a tinge of irony crept into my tones as I replied,

"I'll be very careful what opinions I hold."

"I don't mind the opinions," this astounding young woman took me up gaily. "I never have any of my own, so I don't pay attention to anybody else's. But do be careful of your facts!"

"I'll try to," was all I said. Worth cut in with,

"Do you consider the roof another fact, Bobs?"

"I hope to find facts there," she answered promptly.

"Remember," I said, "your theory means another man up there, and you haven't yet—"

"Please, Mr. Boyne, don't take two and two and make five of them at this stage of the game," she checked me hastily, and I left them together while I made a hurried survey of the hall ceilings, looking for the scuttle. There was no hatchway in view, so I started down to the clerk to make inquiry. As I passed Clayte's open door, Miss Wallace seemed to be adjusting her turban before the dresser mirror, while Worth waited impatiently.

"Just a minute," I called. "I'll be right back," and I ducked into the elevator.