As I drove rapidly up to the house from Casanova Station in the hack, I saw the detective Burns loitering across the street from the Walker place. So Jamieson was putting the screws on--lightly now, but ready to give them a twist or two, I felt certain, very soon.

The house was quiet. Two steps of the circular staircase had been pried off, without result, and beyond a second message from Gertrude, that Halsey insisted on coming home and they would arrive that night, there was nothing new. Mr. Jamieson, having failed to locate the secret room, had gone to the village. I learned afterwards that he called at Doctor Walker's, under pretense of an attack of acute indigestion, and before he left, had inquired about the evening trains to the city. He said he had wasted a lot of time on the case, and a good bit of the mystery was in my imagination! The doctor was under the impression that the house was guarded day and night. Well, give a place a reputation like that, and you don't need a guard at all,--thus Jamieson. And sure enough, late in the afternoon, the two private detectives, accompanied by Mr. Jamieson, walked down the main street of Casanova and took a city-bound train.

That they got off at the next station and walked back again to Sunnyside at dusk, was not known at the time. Personally, I knew nothing of either move; I had other things to absorb me at that time.

Liddy brought me some tea while I rested after my trip, and on the tray was a small book from the Casanova library. It was called The Unseen World and had a cheerful cover on which a half-dozen sheeted figures linked hands around a headstone.

At this point in my story, Halsey always says: "Trust a woman to add two and two together, and make six." To which I retort that if two and two plus X make six, then to discover the unknown quantity is the simplest thing in the world. That a houseful of detectives missed it entirely was because they were busy trying to prove that two and two make four.

The depression due to my visit to the hospital left me at the prospect of seeing Halsey again that night. It was about five o'clock when Liddy left me for a nap before dinner, having put me into a gray silk dressing-gown and a pair of slippers. I listened to her retreating footsteps, and as soon as she was safely below stairs, I went up to the trunk-room. The place had not been disturbed, and I proceeded at once to try to discover the entrance to the hidden room. The openings on either side, as I have said, showed nothing but perhaps three feet of brick wall.

There was no sign of an entrance--no levers, no hinges, to give a hint. Either the mantel or the roof, I decided, and after a half-hour at the mantel, productive of absolutely no result, I decided to try the roof.

I am not fond of a height. The few occasions on which I have climbed a step-ladder have always left me dizzy and weak in the knees. The top of the Washington monument is as impossible to me as the elevation of the presidential chair. And yet--I climbed out on to the Sunnyside roof without a second's hesitation. Like a dog on a scent, like my bearskin progenitor, with his spear and his wild boar, to me now there was the lust of the chase, the frenzy of pursuit, the dust of battle. I got quite a little of the latter on me as I climbed from the unfinished ball-room out through a window to the roof of the east wing of the building, which was only two stories in height.

Once out there, access to the top of the main building was rendered easy--at least it looked easy--by a small vertical iron ladder, fastened to the wall outside of the ball-room, and perhaps twelve feet high. The twelve feet looked short from below, but they were difficult to climb. I gathered my silk gown around me, and succeeded finally in making the top of the ladder.

Once there, however, I was completely out of breath. I sat down, my feet on the top rung, and put my hair pins in more securely, while the wind bellowed my dressing-gown out like a sail. I had torn a great strip of the silk loose, and now I ruthlessly finished the destruction of my gown by jerking it free and tying it around my head.

From far below the smallest sounds came up with peculiar distinctness. I could hear the paper boy whistling down the drive, and I heard something else. I heard the thud of a stone, and a spit, followed by a long and startled meiou from Beulah. I forgot my fear of a height, and advanced boldly almost to the edge of the roof.

It was half-past six by that time, and growing dusk.

"You boy, down there!" I called.

The paper boy turned and looked around. Then, seeing nobody, he raised his eyes. It was a moment before he located me: when he did, he stood for one moment as if paralyzed, then he gave a horrible yell, and dropping his papers, bolted across the lawn to the road without stopping to look around. Once he fell, and his impetus was so great that he turned an involuntary somersault. He was up and off again without any perceptible pause, and he leaped the hedge--which I am sure under ordinary stress would have been a feat for a man.

I am glad in this way to settle the Gray Lady story, which is still a choice morsel in Casanova. I believe the moral deduced by the village was that it is always unlucky to throw a stone at a black cat.

With Johnny Sweeny a cloud of dust down the road, and the dinner- hour approaching, I hurried on with my investigations. Luckily, the roof was flat, and I was able to go over every inch of it. But the result was disappointing; no trap-door revealed itself, no glass window; nothing but a couple of pipes two inches across, and standing perhaps eighteen inches high and three feet apart, with a cap to prevent rain from entering and raised to permit the passage of air. I picked up a pebble from the roof and dropped it down, listening with my ear at one of the pipes. I could hear it strike on something with a sharp, metallic sound, but it was impossible for me to tell how far it had gone.

I gave up finally and went down the ladder again, getting in through the ball-room window without being observed. I went back at once to the trunk-room, and, sitting down on a box, I gave my mind, as consistently as I could, to the problem before me. If the pipes in the roof were ventilators to the secret room, and there was no trap-door above, the entrance was probably in one of the two rooms between which it lay--unless, indeed, the room had been built, and the opening then closed with a brick and mortar wall.

The mantel fascinated me. Made of wood and carved, the more I looked the more I wondered that I had not noticed before the absurdity of such a mantel in such a place. It was covered with scrolls and panels, and finally, by the merest accident, I pushed one of the panels to the side. It moved easily, revealing a small brass knob.

It is not necessary to detail the fluctuations of hope and despair, and not a little fear of what lay beyond, with which I twisted and turned the knob. It moved, but nothing seemed to happen, and then I discovered the trouble. I pushed the knob vigorously to one side, and the whole mantel swung loose from the wall almost a foot, revealing a cavernous space beyond.

I took a long breath, closed the door from the trunk-room into the hall--thank Heaven, I did not lock it--and pulling the mantel-door wide open, I stepped into the chimney-room. I had time to get a hazy view of a small portable safe, a common wooden table and a chair--then the mantel door swung to, and clicked behind me. I stood quite still for a moment, in the darkness, unable to comprehend what had happened. Then I turned and beat furiously at the door with my fists. It was closed and locked again, and my fingers in the darkness slid over a smooth wooden surface without a sign of a knob.

I was furiously angry--at myself, at the mantel door, at everything. I did not fear suffocation; before the thought had come to me I had already seen a gleam of light from the two small ventilating pipes in the roof. They supplied air, but nothing else. The room itself was shrouded in blackness.

I sat down in the stiff-backed chair and tried to remember how many days one could live without food and water. When that grew monotonous and rather painful, I got up and, according to the time-honored rule for people shut in unknown and ink-black prisons, I felt my way around--it was small enough, goodness knows. I felt nothing but a splintery surface of boards, and in endeavoring to get back to the chair, something struck me full in the face, and fell with the noise of a thousand explosions to the ground. When I had gathered up my nerves again, I found it had been the bulb of a swinging electric light, and that had it not been for the accident, I might have starved to death in an illuminated sepulcher.

I must have dozed off. I am sure I did not faint. I was never more composed in my life. I remember planning, if I were not discovered, who would have my things. I knew Liddy would want my heliotrope poplin, and she's a fright in lavender. Once or twice I heard mice in the partitions, and so I sat on the table, with my feet on the chair. I imagined I could hear the search going on through the house, and once some one came into the trunk-room; I could distinctly hear footsteps.

"In the chimney! In the chimney!" I called with all my might, and was rewarded by a piercing shriek from Liddy and the slam of the trunk-room door.

I felt easier after that, although the room was oppressively hot and enervating. I had no doubt the search for me would now come in the right direction, and after a little, I dropped into a doze. How long I slept I do not know.

It must have been several hours, for I had been tired from a busy day, and I wakened stiff from my awkward position. I could not remember where I was for a few minutes, and my head felt heavy and congested. Gradually I roused to my surroundings, and to the fact that in spite of the ventilators, the air was bad and growing worse. I was breathing long, gasping respirations, and my face was damp and clammy. I must have been there a long time, and the searchers were probably hunting outside the house, dredging the creek, or beating the woodland. I knew that another hour or two would find me unconscious, and with my inability to cry out would go my only chance of rescue. It was the combination of bad air and heat, probably, for some inadequate ventilation was coming through the pipes. I tried to retain my consciousness by walking the length of the room and back, over and over, but I had not the strength to keep it up, so I sat down on the table again, my back against the wall.

The house was very still. Once my straining ears seemed to catch a footfall beneath me, possibly in my own room. I groped for the chair from the table, and pounded with it frantically on the floor. But nothing happened: I realized bitterly that if the sound was heard at all, no doubt it was classed with the other rappings that had so alarmed us recently.

It was impossible to judge the flight of time. I measured five minutes by counting my pulse, allowing seventy-two beats to the minute. But it took eternities, and toward the last I found it hard to count; my head was confused.

And then--I heard sounds from below me, in the house. There was a peculiar throbbing, vibrating noise that I felt rather than heard, much like the pulsing beat of fire engines in the city. For one awful moment I thought the house was on fire, and every drop of blood in my body gathered around my heart; then I knew. It was the engine of the automobile, and Halsey had come back. Hope sprang up afresh. Halsey's clear head and Gertrude's intuition might do what Liddy's hysteria and three detectives had failed in.

After a time I thought I had been right. There was certainly something going on down below; doors were slamming, people were hurrying through the halls, and certain high notes of excited voices penetrated to me shrilly. I hoped they were coming closer, but after a time the sounds died away below, and I was left to the silence and heat, to the weight of the darkness, to the oppression of walls that seemed to close in on me and stifle me.

The first warning I had was a stealthy fumbling at the lock of the mantel-door. With my mouth open to scream, I stopped. Perhaps the situation had rendered me acute, perhaps it was instinctive. Whatever it was, I sat without moving, and some one outside, in absolute stillness, ran his fingers over the carving of the mantel and--found the panel.

Now the sounds below redoubled: from the clatter and jarring I knew that several people were running up the stairs, and as the sounds approached, I could even hear what they said.

"Watch the end staircases!" Jamieson was shouting. "Damnation-- there's no light here!" And then a second later. "All together now. One--two--three--"

The door into the trunk-room had been locked from the inside. At the second that it gave, opening against the wall with a crash and evidently tumbling somebody into the room, the stealthy fingers beyond the mantel-door gave the knob the proper impetus, and--the door swung open, and closed again. Only--and Liddy always screams and puts her fingers in her ears at this point-- only now I was not alone in the chimney room. There was some one else in the darkness, some one who breathed hard, and who was so close I could have touched him with my hand.

I was in a paralysis of terror. Outside there were excited voices and incredulous oaths. The trunks were being jerked around in a frantic search, the windows were thrown open, only to show a sheer drop of forty feet. And the man in the room with me leaned against the mantel-door and listened. His pursuers were plainly baffled: I heard him draw a long breath, and turn to grope his way through the blackness. Then--he touched my hand, cold, clammy, death-like.

A hand in an empty room! He drew in his breath, the sharp intaking of horror that fills lungs suddenly collapsed. Beyond jerking his hand away instantly, he made no movement. I think absolute terror had him by the throat. Then he stepped back, without turning, retreating foot by foot from The Dread in the corner, and I do not think he breathed.

Then, with the relief of space between us, I screamed, ear- splittingly, madly, and they heard me outside.

"In the chimney!" I shrieked. "Behind the mantel! The mantel!"

With an oath the figure hurled itself across the room at me, and I screamed again. In his blind fury he had missed me; I heard him strike the wall. That one time I eluded him; I was across the room, and I had got the chair. He stood for a second, listening, then--he made another rush, and I struck out with my weapon. I think it stunned him, for I had a second's respite when I could hear him breathing, and some one shouted outside:

"We--Can't--get--in. How--does--it--open?"

But the man in the room had changed his tactics. I knew he was creeping on me, inch by inch, and I could not tell from where. And then--he caught me. He held his hand over my mouth, and I bit him. I was helpless, strangling,--and some one was trying to break in the mantel from outside. It began to yield somewhere, for a thin wedge of yellowish light was reflected on the opposite wall. When he saw that, my assailant dropped me with a curse; then--the opposite wall swung open noiselessly, closed again without a sound, and I was alone. The intruder was gone.

"In the next room!" I called wildly. "The next room!" But the sound of blows on the mantel drowned my voice. By the time I had made them understand, a couple of minutes had elapsed. The pursuit was taken up then, by all except Alex, who was determined to liberate me. When I stepped out into the trunk-room, a free woman again, I could hear the chase far below.

I must say, for all Alex's anxiety to set me free, he paid little enough attention to my plight. He jumped through the opening into the secret room, and picked up the portable safe.

"I am going to put this in Mr. Halsey's room, Miss Innes," he said, "and I shall send one of the detectives to guard it."

I hardly heard him. I wanted to laugh and cry in the same breath--to crawl into bed and have a cup of tea, and scold Liddy, and do any of the thousand natural things that I had never expected to do again. And the air! The touch of the cool night air on my face!

As Alex and I reached the second floor, Mr. Jamieson met us. He was grave and quiet, and he nodded comprehendingly when he saw the safe.

"Will you come with me for a moment, Miss Innes?" he asked soberly, and on my assenting, he led the way to the east wing. There were lights moving around below, and some of the maids were standing gaping down. They screamed when they saw me, and drew back to let me pass. There was a sort of hush over the scene; Alex, behind me, muttered something I could not hear, and brushed past me without ceremony. Then I realized that a man was lying doubled up at the foot of the staircase, and that Alex was stooping over him.

As I came slowly down, Winters stepped back, and Alex straightened himself, looking at me across the body with impenetrable eyes. In his hand he held a shaggy gray wig, and before me on the floor lay the man whose headstone stood in Casanova churchyard--Paul Armstrong.

Winters told the story in a dozen words. In his headlong flight down the circular staircase, with Winters just behind, Paul Armstrong had pitched forward violently, struck his head against the door to the east veranda, and probably broken his neck. He had died as Winters reached him.

As the detective finished, I saw Halsey, pale and shaken, in the card-room doorway, and for the first time that night I lost my self-control. I put my arms around my boy, and for a moment he had to support me. A second later, over Halsey's shoulder, I saw something that turned my emotion into other channels, for, behind him, in the shadowy card-room, were Gertrude and Alex, the gardener, and--there is no use mincing matters--he was kissing her!

I was unable to speak. Twice I opened my mouth: then I turned Halsey around and pointed. They were quite unconscious of us; her head was on his shoulder, his face against her hair. As it happened, it was Mr. Jamieson who broke up the tableau.

He stepped over to Alex and touched him on the arm.

"And now," he said quietly, "how long are you and I to play OUR little comedy, Mr. Bailey?"