“One moment longer,” said Darwin. “I wish to be sure this instrument is exactly set before I use it.” He exchanged a strange look with Ledyard, then bent and made a small adjustment to the brass fan that was fixed to the front of the device above the long pendulum. He squinted along the line of sight, moved the lantern a fraction, and at last seemed satisfied. He straightened up.
“I ask five minutes of your time. Then, if you wish, Dr. Ledyard will be dealt with as Mr. Alderton has suggested. I want to use this device to explain the events at the pit. It was made for us, at my specification, by Harrison the clock maker at Kings Lynn.”
“And at monstrous cost,” grumbled Pole. “It should be made of gold for the price he charged.”
“Hold your fire, Jacob,” said Darwin. “You will see that it is worth the investment we made. Before I engage the gears, let me ask, what did each of you see tonight, when you were down there in the pit?”
There was a moment’s silence. “Dr. Ledyard was attacking Mr. Alderton,” said Pole gruffly. Bretherton nodded his agreement.
“Right. And before that. What did you see, Alice?”
She looked puzzled, and glanced at Philip Alderton next to her before she answered. “Before the attack? Philip and I were alone there at first. There was really nothing to see. Just the walls of the pit, and the sky. Was it not so, Philip?”
Alderton shrugged and looked bored. “No Immortal, if that’s what you’re trying to get to, even though the conditions were supposed to be perfect for its appearance. I had gone there to tell Alice to stop that nonsense, and to return to the manor. I knew from personal experience that there are dangers in that pit. That was my main interest—not sight-seeing down there. Get to the point, and we can all end the evening.”
Darwin looked finally at Ledyard, who first seemed ready to speak, then bowed his head and remained silent.
Darwin shrugged. “I am sure that you all believe that you are telling me the truth,” he said. “It is easy to prove that none of you is telling me the whole truth. The pit is deep, as we all know. But it is not so deep as a well. From where you were standing, you could all clearly see two other things: the moon, and the mill.”
Alice nodded. “Of course.” She turned to Alderton. “Remember, Philip, I said that I could distinguish the small flints in the pit walls, even without the need of a lantern.”
“And of what possible importance is that?” said Alderton.
“Most important,” replied Darwin. “For if you could see the moon, then you could also see the mill, outlined against the moon. That will always be the arrangement when the full moon first rises. As it comes high enough in the sky to be seen from the bottom of the pit, the mill stands so that the sweeps of the mill intercept its light. Now recall, if you can, the words of Gerald Alderton’s warning—for that is what his message was intended to be. Who can remember it?”
“I do,” said Alice softly. “Moon full on the hill.”
“As it was tonight,” said Darwin. “And next?”
“Wind strong on the mill.”
“So that, had the sweeps been left free to turn, they would be moving round at a good pace. If you watch them closely, you will find that their speed depends little on the force of the wind, provided that it is beyond a certain strength. The sweeps turn at a rate that is close to constant. What is our next condition?”
“No cloud to the East,” whispered Alice.
“And why is that so important?” said Darwin. “Why, for the obvious reason. The moon would not otherwise be visible. So we had Gerald Alderton’s conditions. A moon, shining into the pit through the sweeps of the mill. Are these enough to call forth the Beast of the Pit, to rend and to kill? Are they sufficient, or is some other factor needed also? Well, that is what I propose to test, with the aid of this instrument.” He pointed to the iron and brass clockwork assembly in front of him.
The others were looking at him skeptically, except for James Ledyard who was shaking his head in vehement objection.
“Don’t do it,” he said. “For God’s sake, Dr. Darwin, no sane man will seek to conjure demons, no matter where they dwell.”
Darwin hesitated, weighing Ledyard’s words. “That is quite true,” he said at last. “Unless we raise them to exorcise them, once and for ever. It must be done. All of you, watch closely now, keep your eyes fixed on the lantern beam.”
He unshuttered the lamp, and the beam shone out the length of the room, behind Darwin’s mechanism. At a signal from him, Pole stood up and quietly snuffed the candles in their ornate mounts along the walls. He closed the heavy curtains. The room was silent, lit only by the single lantern.
Darwin bent over the instrument in front of the lamp, and released a metal catch on its side. There was a steady whirring noise and the metal fan in front began a slow revolution. Darwin hurried back along the table, paying out a length of line that was attached to the side of the mechanism. He drew it taut and took up a position standing behind the others. The fan blades intercepted the lantern beam, throwing a flickering pattern of light and dark across the interior of the room.
Darwin increased the tension on the line he was holding, and the moving blades turned faster, black bars across the bright beam. He was making delicate adjustments, seeking a particular speed of rotation. Another sound began to grow in the room. Above the steady whir of the machinery there was growing a labored, tortured breathing. It was a strangled growl, deep in the throat.
Alice had turned her head away from the beam. She gave a scream of terror. By her side, Philip Alderton, the veins in his neck and head congested with blood, began to lurch to his feet. The wooden arms of his chair splintered like dry twigs in the grip of his powerful hands. He began to turn toward Alice, huge in the flickering light of the lantern beam.
Darwin released the line. Before Alderton had fully risen, he leaned over him from behind. The doctor’s hands, strong and precise, pressed firmly on Alderton’s carotid arteries. Grunting in his throat, Alderton tried to bring his hands up to free himself from Darwin’s grip. After a few seconds, he swayed forward and fell unconscious to the thick carpet.
Darwin released him as he fell. “Let’s have lights, and quickly,” he said. He took a deep breath, as though he had been starved of air for several minutes. “You, Bretherton, bring servants here and have your Master carried up to his bed. I judge that he will be unconscious at least five minutes. Give him nothing but water when he wakens, and tend him closely until Dr. Ledyard or I have the opportunity to examine him.”
He went over to the clockwork machine and halted the whirling fan. Pole lit a spill from the lantern on the table and applied it to the candles in their wall brackets. As the room grew light again, James Ledyard gave a long sigh. He shook his head as four servants helped Bretherton to lift Alderton’s great body and bear it from the room.
“That is what my mind refused to accept,” he said. “I feared it, but it went against all my training and my innermost beliefs. I told myself that such a thing was impossible. But I was wrong.”
“Not wholly wrong, I think.” Darwin looked sympathetically at the young doctor. “Wrong in detail, but not in essence. Your instinct told the man, but not the method.” He went over to the curtains and opened them wide. The full moon was still visible, now high in the sky.
“Well past midnight, I would judge,” he said. “We must remain awake until Philip Alderton revives. Miss Alice, will you see Bretherton and ask for food to be brought here. Cold roast and a pie will suffice.” He turned again to Ledyard. “And what suspicions had you developed about Philip Alderton? I can perhaps guess some of them, from your behavior when first we met. You will recall your reluctance to involve me in treating his wounds.”