For a moment I didn't say anything. I was kind of quivering in my insides with the excitement of it. O'Mally hadn't got anything to beat _this_. We swung lazily back and forth, my hand clasped below Troop's, and the fat man giving up in despair. Only when my wrist bag caught him on the hat, he gave me one reproachful look and then settled the hat hard on his head to show me what he was suffering.

The train began to slow up, white-tiled walls glided past the windows, and the conductor opened the door and yelled, "Ninety-sixth Street."

It had worked out just right. I had my information and here was where I got off. I thanked Troop for the ride I'd had off him, told him I'd give him his nickel tomorrow, and forging to the door like the _Oregon_ going round Cape Horn, scrambled out.

Himself wasn't at home to tell things to-it was one of his late nights-so I took a call for Mr. Whitney's house and told him I'd got the stuff for him-_real_ stuff. He said to come down that evening at half-past eight, they'd all be there. And after a gla.s.s of milk and a soda cracker-I hadn't time or appet.i.te for more-out I lit, as excited as if I was going to a six-reel movie.

I was late and ran panting up the steps of the big, grand house in the West Fifties. I'd been there before, and as I stood waiting in the vestibule I couldn't but smile thinking of that other time when I was so scared, and Himself-he was "Mr. Babbitts" then-had had to jolly me up.

He didn't know me as well then as he does now, bless his dear, faithful heart!

The unnatural solemn butler wasn't on the job tonight. Mr. George opened the door for me and showed me into that same room off the hall, with the gold-mounted furniture and the pale-colored rugs and the lights in crystal bunches along the walls. A fire was burning in the grate, its red reflection leaping along the uncovered s.p.a.ces of floor, polished and smooth as ice. On a center table, all gilt and gla.s.s, was a common student lamp, looking cheap and mean in that quiet, rich, glittering room, and beside it were some sheets of paper and several pencils. Old Mr. Whitney and George were there, also Jack Reddy, but O'Mally hadn't come yet.

I told them what Troop had said and they listened as silent as the grave, not batting an eye while I spoke. You didn't have to guess at what they thought. It was in the air. The first real move had been made.

When I finished, Mr. George, who had been making notes on one of the bits of paper, threw down his pencil, and gave a long, soft whistle. The old man, sitting by the fire looking into it, his hands clasped loosely together, the fingers moving round each other-which was a way he had when he was thinking-said very quiet:

"Thank you, Molly-you've done well."

"This puts Ford in the center of the stage," said Mr. George, then turning to his father, "Pretty conclusive, eh, Governor?"

The old man grunted without looking up, his face in the firelight, heavy and brooding.

Jack rose and leaning over Mr. George's shoulder looked at the scribbled notes:

"Left soon after the Barry girl, came back about 6.15 and went to the Azalea Woods Estates offices. That would have been about fifteen to twenty minutes after Harland. Came out about half-past six and was in the elevator when the body fell."

"Positive proof that he was in the rooms with Harland," said Mr. George, "and equally positive proof he was not the man seen by the Meagher child."

"Evidently two men," said Jack.

"Two men," echoed Mr. George. Then turned to me, "Where was Miss Whitehall? Did this Troop fellow say anything about when _she_ left?"

Jack looked up from the notes and cast a quick, sharp glance at me.

"She'd gone already, of course?" he said.

"Yes, she'd gone," I answered. "Anyway, Iola Barry said she always went before six." Then in answer to Mr. George, "I didn't ask Troop anything about her. I didn't think there was any need and I was afraid I'd get him curious if I wanted to know too much."

"Good girl," came from the old man in a rumbling growl.

At that moment there was a ring at the bell. With an exclamation of "O'Mally," Mr. George jumped up and went into the hall. It was O'Mally, red as a lobster, and with an important roll to his walk. He stood in the door and looked at the old man in a triumphant way till you'd suppose he'd got the murderer outside chained to the door handle.

Babbitts, who'd come to know him well on the trip to Rochester, said he was a first-rate chap and as sharp as a needle, if you could get over his taking himself so dead serious.

When he heard my story some of the starch was taken out of him, but I will say he was so interested that, after the first shock, he forgot to be jealous and was as keen as mustard.

"Two men sure enough," he agreed. "And two men who operated together, one of them in that back room."

"How do you make that out?" asked Jack.

"I'll show you-I've been busy this afternoon." He looked round, selected a gold-legged chair and pulling it to the table, sat down, and taking a fountain pen from his pocket, drew a sheet of paper toward him. "Right next to the church, as you may remember, there are three houses, dwellings. The one nearest the church is occupied by a private party, the two beyond have been thrown together and are run as a boarding house. The last of the two has a rear extension built out to the end of the lot. The day we examined the Azalea Woods Estates I saw that the windows of that extension commanded the side wall of the Black Eagle Building.

"This afternoon I went to the boarding house, said I was a writer looking for a quiet place to work, and asked if they had an empty room in the extension. They had one, not yet vacated, but to be in February.

It was occupied by an old lady-Miss Darnley-who being there gave me permission to see it.

"Now here's where I get busy," he drew the paper toward him and began marking it with long straight lines and little squares. "Miss Darnley is a nice old lady and some talker. We got ga.s.sing, as natural as could be, on the horrible suicide of Mr. Harland, so close by. She took me to the window and showed me where his offices were, and told me how it was her habit, every evening as night fell, to sit in that window and watch the lights start out, especially in the Black Eagle Building. She sat there always till half-past six, when the first gong sounded for dinner. And if I took the room I was to be sure and go down then-the food was better-she always did.

"By a little skillful jollying-mostly surprise at her powers of observation and memory-I got from her some significant facts about the lights on the seventeenth floor of the Black Eagle Building on the night of January fifteenth. The Harland suite-she'd located it from the papers-was lit till she went down to dinner. Wonderful how she'd remembered! How was the floor below-bet a hat she couldn't remember _that_! She could, and proud as a peac.o.c.k, gave a demonstration. All dark as it usually was at six, then a light in the fourth window-Azalea Woods Estates, private office. Then that goes out and the three front windows are bright. Just before she goes down to dinner, she notices that every window on the whole sweep of the seventeenth floor is dark except that fourth one-Azalea Woods Estates, private office."

He stopped and pushed the paper he'd been drawing on across to George.

"Here it is, with the time as I make it marked on each window."

Jack and Mr. George leaned down studying the diagram and Mr. Whitney slowly rose and coming up behind them looked at it over their shoulders.

All their faces, clear in the lamplight, with O'Mally's red and proud glancing sideways at the drawing, were intent and frowning.

"Let's see how the thing works out," said Mr. George, taking up a pencil and pulling a sheet of paper toward him. Mr. Whitney straightened up with a sort of tired snort and slouched back to his seat by the fire.

Mr. George began, figuring on the paper:

"The Azalea Woods Estates were cleared at six-all lights out. At a few minutes after, Harland came down the stairs and entered them, going through to the private office and switching on the light, or meeting someone there who switched it on as he came. Some ten or fifteen minutes later Ford came in. That's evidently the moment, according to your old lady, when the private office was dark and the other two lit up. Just before 6:30-time when Ford left-the front rooms are all dark again. Good deal of a mess to me." He tilted back in his chair so that he could see his father. "What do you make of it, Governor?"

"Let's hear what O'Mally has to say first," said Mr. Whitney. They couldn't see his face which was turned to the fire, but I could, and it had a slight, amused smile on it.

O'Mally sprawled back in his chair with his chest thrown out:

"Well, I don't like to commit myself so early in the game, but there are a few things that seem pretty clear. Though the Azalea Woods Estates were dark when Harland came down somebody was there."

"Who?" asked Jack.

O'Mally looked sort of pitying at him:

"His murderer. This man didn't attempt the job alone. Must have held Harland in talk in the private office till later when Tony Ford came in and helped, if he didn't do the actual killing. When _that_ was over Ford went, leaving the other man to carry out the sensational denouement."

"What could have been Ford's motive?" said Mr. George. "Did he know Harland?"

O'Mally grinned.

"Oh, we'll find a motive all right. Wait till we've turned up the earth in his tracks. Wait a few days."

"This 'other man,' O'Mally," said Mr. Whitney, "have you any ideas about him?"

"There you got me stumped," said the detective. "Of course we don't know Harland's inner life-had he an enemy and if so who? But-" he paused and let his glance move over the faces of the two young men. "_If_ the thing hadn't been physically impossible I'd have turned my searchlight eye on Johnston Barker."

"Barker!" exclaimed Mr. George. "But Barker was--"

O'Mally interrupted him with a wave of his hand-

"I _said_ it was physically impossible."