It was bright moonlight when Forrester left the house and walked south on Sheridan Road. He had decided to walk to Lucy's, believing that he would attract less attention, both on the way and after reaching his destination, than if he used his roadster. Though wayside trees cast great shadows across the road, and the gloom near bordering hedgerows, or the underbrush of vacant tracts, afforded partial concealment, Forrester looked with apprehension upon the brilliancy of the night. Fortunately for his plans, large clouds began shortly to drift over the moon. The gloom was more intense during these moments of darkness because of the transition from periods of strong moonlight.

The night was unusually still, undoubtedly because of an approaching storm, and few people seemed to be abroad. Only two motor cars passed him during the journey between his home and Jasper lane. One of these passed at a time when the moon was shining brightly and Forrester was sure that it was Melville's limousine. At the moment, he was walking in the deep shadow of a high hedge and was probably invisible to the occupants of the car. It was a providential circumstance, for to be stopped and questioned at this time would not only cause delay, but might attract undesirable attention.

Reaching Jasper lane, Forrester kept to the grass at the side, and walking slowly, succeeded in approaching the oak tree without any sound that would be audible to others than himself. He paused, listening long and intently. The silence seemed almost palpable, its noiseless fingers clutching at him from the darkness. A momentary flash of the moon gave him his bearings. During the succeeding darkness, Forrester, stooping low, carefully felt his way past the tree and down the path toward Lucy's cottage. Unless the colored woman had secured another dog, Forrester was sure that he could reach her door unnoticed. It was then his purpose to tie her fast and either frighten her into some helpful admission or else discover for himself some clue possibly overlooked by the police.

The cottage stood dark and silent in its little clearing. Forrester reached it without hearing a sound, but he had a momentary feeling of uneasiness when the moon shone full upon him as he crossed the clearing. At the door he paused to consider. Was the woman away? Or had she retired for the night? If the latter, then he would probably be able to surprise her while she slept. Forrester placed his hand on the doorknob and turned it slowly and quietly. Then he exerted a gentle pressure, and was gratified, though astonished, to find that the door opened. Fearful of squeaking hinges Forrester moved the door inward an inch at a time, and entering, closed it in the same careful way. There was no key in the lock, but running his hand along the edge of the door, Forrester discovered a bolt which he softly pushed into place.

Forrester took out the muffler and wound it about his neck and face until only his eyes were exposed. Then he pulled his cap down so that its vizor shadowed even these. With intermittent and cautious flashes of his pocket lamp he found that the room was unoccupied and the door leading to what he believed to be Lucy's bedroom closed. This he approached with wary tread and opened the door slowly and softly. A flash of his light showed that the bedroom was also deserted. Lucy was not at home! It was a wonderful opportunity that might be interrupted at any moment, so Forrester worked fast. He considered it immaterial what the woman might discover after he was gone. Any disorder she would probably attribute to another visit by the police.

Forrester tore the coverings from the bed and scattered the contents of drawers on the floor. His search was unrewarded. There was not a line of writing anywhere; no concealed arms, Bolshevik literature or suspicious bottles; absolutely nothing to form the slightest clue. He then carried his search into the sitting room with equally unsuccessful results. Forrester received an uncomfortable shock as he turned his pocket lamp into the aquarium and saw the slimy bodies of the snakes writhe uneasily under the glare of the light.

Thus far the search had been fruitless and discouraging, but the sight of the snakes in their glass prison started Forrester's mind to working. What was the real purpose of these snakes? Their uncanny, loathsome bodies were repellent to the strongest man. Repellent! The word was illuminative. Was not one of its definitions "drive back"? Was this the actual purpose of the snakes?

Forrester fixed the button on his pocket lamp to keep the light steady, and laid it on the center table to illumine his work. Lifting the stand on which the aquarium rested he placed it near the middle of the room and pulled aside the heavy rug.

Directly beneath the spot where the aquarium stood was a square trapdoor in the floor!

Forrester stooped, placed two fingers in a hole, evidently provided for the purpose, lifted the section of carefully fitted flooring and set it to one side. Taking his light from the table and turning its rays into the opening Forrester saw a ladder leading into a cellar beneath the cottage. Swiftly he dropped his legs through the hole and descended.

The underground room in which he found himself was smaller than the space covered by the cottage. The walls were of large rough stones, showing evidence of dampness. Along these walls was piled litter of a varied nature—old barrels, boxes, empty food tins and the broken remains of furniture. Against the front wall, at a point almost under the entrance door, stood an old, dilapidated sideboard. It attracted Forrester's attention because he could not conceive how such a large object had been brought into the cellar through the small trap. It was the only thing in the cellar that could be readily moved, and Forrester had an inspiration to look behind it. At the first effort the sideboard swung out from the wall on smooth-running casters that strangely had apparently not been affected by the dampness of the cellar.

Moving the sideboard disclosed a small, rough-board door in the wall. This Forrester opened and flashed his light into the space beyond. It seemed to be a narrow passage, the floor a little below the level of the cellar. Forrester dropped into the passage and started along it, throwing his light about him and studying its formation. The floor was sandy, the walls of solid rock, and the roof appeared to have been formed by a multitude of interlacing tree and plant roots. The average width of the passage was about five feet and its height somewhere between ten and twelve. Forrester's trained eye saw instantly that it was the work of Nature, not of man. At some remote period a cleft had been riven in the solid rock and the intertwined roots above prevented the caving in of the surface soil.

A momentary sparkle on the ceiling caught Forrester's eye. He then discovered that electric lights were hung from the roof at regular intervals. They were beyond his reach, and as no connection or switch along the walls had been discovered, Forrester concluded that the lights could be operated only from some point inside the cottage.

Presently Forrester came to an indentation in the wall on his right, forming a sort of shelf. On this rested two bright steel cylinders about the size of the small fire extinguisher he carried in his car. To one of the cylinders was attached a five-foot length of a slender rubber tubing which connected it with one of the rubber death masks he knew only too well. Here at last was evidence beyond dispute. Forrester did not meddle with the cylinders. The slightest mistake made by one unaccustomed to them might release the deadly gas he had reason to believe they contained. In that confined space its action would be swift and sure.

Continuing along the passage Forrester finally came to the end. At this point it widened out slightly into a small chamber. At one side a ladder led up into a mass of tangled tree roots that hung in fantastic shapes, which gave Forrester an uncomfortable feeling that he had stumbled into a veritable den of snakes. Forcing back this feeling of revulsion he climbed the ladder.

Here the handiwork of man was in evidence. He was ascending into a space that had been hollowed out of the heart of a tree. Above his head was a small wooden trapdoor held in place by a wood slide or bolt. Releasing the bolt allowed the door to drop silently downward on hinges formed of stiff leather. A package fell into his hands, followed by a draft of air laden with the scent of summer woods. Pushing up his light Forrester recognized the hollow in the oak tree. He saw also that the upper side of the trapdoor was so prepared that it would seem like part of the tree to anyone investigating from above.

At last the most vital secret of the "Friends of the Poor" was in his hands—the method by which they had so mysteriously secured their toll under the very eyes of the detectives.

Forrester examined the small, flat package in his hand. Someone had placed a contribution in the tree that night. Then Forrester shivered. The scoundrels would come to collect at any moment! He was shut in at the far end of a narrow passage, the only way of escape leading back through the cottage where they would enter. If they met him here his end would be sure and his disappearance a mystery forever. Hastily he climbed down the ladder and was about to go when several objects drew his attention. The temptation to investigate these before he left was too strong to resist and Forrester lingered a moment or two longer.

All the paraphernalia that had made possible the ghostly illusions, which had frightened others and puzzled him, now lay revealed as nothing but mean claptrap. On the wall hung a group of rusty chains, a small megaphone for throwing the voice and an old locomotive bell. In one corner stood a tin similar to a paint can. This, Forrester found, contained a preparation commonly known as phosphorescent paint and a nearby glove, which smelled strongly of the substance, solved the riddle of the flaming hand which had impressed even the phlegmatic Green. The greatest curiosity of all, however, was a black tube standing against the wall. Forrester instantly remembered the appearance of something of this kind in Humphrey's photograph. On examination it proved to be a homemade periscope. By pushing it up into the opening in the oak tree it was probably possible for a person in the cave to ascertain what was occurring on the surface. Forrester did not wait to experiment, for he was sure that on the night of the Italians' visit someone was taking in the scene and the projecting end of the periscope had been picked up by the camera.

Forrester now hurried down the passage. Unquestionably he had lingered longer than was wise, and a quick escape was imperative. As he passed back through the passage Forrester's engineering training caused him to note certain things about him. Though the rocky walls and the sand beneath his feet were now dry, he saw indications that the cleft must serve as a drain for the neighborhood. In the winter it was probably a well; full of cold, stagnant water, which, he surmised, accounted for the peculiar inactivity of the "Friends of the Poor" after the winter rains and snow fell.

Before he reached the end of the passage Forrester was startled to hear a grating sound, followed by a slight thud.

Like a flash the truth came to him. Someone had discovered the moved sideboard and open door and surmising that the visitor was still in the cave had shut him in.

Forrester paused to reflect. It would be useless to try and force his way out. Even if he could get through the door, which he doubted, there was no telling how many of the band were in the cottage. Forrester was unarmed, as he had expected to deal only with Lucy, and a battle with more than one man would be an unequal struggle. To make matters worse, his electric lamp, which had been in constant use since he entered the cottage, now gave out. The bulb still glowed, but with a dull light that had no power. Forrester flung the lamp down and felt his way back toward the tree. He reasoned that as a package had been placed in the tree it was more than probable that detectives were concealed nearby. To climb into the opening in the tree, attract their attention by shouting, and then give directions for reaching him, seemed the only solution.

Continued calls, however, brought no response. Either there were no detectives there, or else his cries for help, which necessarily had to be subdued, were acting on superstitious minds and accomplishing just the opposite of what he intended—driving help away. Forrester ceased his calls and climbed slowly down into the cave once more.

Suddenly the place was brilliantly illuminated by the turning on of the electric lights over his head. The meaning of this was clear. The time had come when he must fight for his life and Forrester looked about for a weapon. There was nothing that would serve his purpose. Then he recollected the cylinders. Who knew better than these men their death-dealing power? With these cylinders in his hands would it not be possible to hold his assailants at bay—even to overcome them? Forrester dashed down the passage to reach the cylinders before his enemies. It was too late! As he rounded a slight curve in the rocky cleft he saw the figure of a man only a short distance away. Still there might be time. He could see the depression where the cylinders rested and the man was some distance on the other side. Forrester kept on, but his hopes fell as he saw the man reach the spot first and stop.

Forrester also came to a halt and the two men surveyed each other in silence. Completely covering the man's head and shoulders was a black hood. Through two slits Forrester could see the sparkle of his eyes. Forrester recalled Prentice's description of the two hooded men who had attacked him and realized that at last he was face to face with the "Friends of the Poor."

The man moved forward. As he approached, his body slightly crouched like a wrestler waiting for his opening, Forrester took heart. If it was simply to be a hand to hand contest and the men came only one at a time, then there was some hope.

Forrester kept the man off at first with his fists, but at length they closed and a desperate struggle began. Back and forth they tugged and pulled, neither man seemingly gaining any advantage. All at once Forrester saw the cylinders at his side and suddenly realized that throughout the struggle the man had been slowly dragging him along toward these death machines. And with the realization he saw the man reach out and seize the one with the rubber mask attached.

From that moment the battle changed. Forrester's one thought was to keep the mask away from his face, while the man's main effort was evidently directed toward placing it there. Presently Forrester detected the peculiar odor of the gas. Either the cylinder had been accidentally opened in the struggle or the man had intentionally released the gas. As the mask was directed toward Forrester, and only a few inches from his face, he received the full effect of the fumes, while the man was partially protected from its effect. Forrester felt himself weakening, as he had on the night of the battle in Jasper lane.

With a last despairing effort he tripped his antagonist and as they fell Forrester managed to come down on top. Slowly he forced the mask over the man's hooded face and just as he had it in place Forrester sank down unconscious.