So saying, he crossed to the book shelves, at the approximate place where she had reported seeing the apparition that haunted the library. He lifted a dozen books off a shelf and put them to one side. Then he knocked upon the wall behind. It gave back a muffled, hollow sound. He nodded in satisfaction, and then gave the entire section of shelving the closest scrutiny.
Presently he found what he sought — after having removed half the books from the shelving there — a small lever concealed behind a row of books. He depressed it. Instantly there was a soft thud — like the sound a book might make when it struck the carpet — and the section sagged forward, opening into the room like a door ajar. Mrs. Ashcroft gasped sharply.
“What on earth is that, Mr. Pons?”
“Unless I am very much mistaken, it is a passage to the abandoned right-of-way of the Nunhead-Crystal Palace Line — and the temporary refuge of your library ghost.”
He pulled the shelving further into the room, exposing a gaping aperture which led into the high bank behind that wall of the house, and down into the earth beneath. Out of the aperture came a voice which was certainly that of an inebriated man, raucously singing. The voice echoed and reverberated as in a cavern below.
“Pray excuse us, Mrs. Ashcroft,” said Pons. “Come, Parker.”
Pons took a flashlight from his pocket and, crouching, crept into the tunnel. I followed him. The earth was shored up for a little way beyond the opening, then the walls were bare, and here and there I found them narrow for me, though Pons, being slender, managed to slip through with less difficulty. The aperture was not high enough for some distance to enable one to do more than crawl, and it was a descending passage almost from the opening in Mrs. Ashcroft’s library.
Ahead of us, the singing had stopped suddenly.
“Hist!” warned Pons abruptly.
There was a sound of hurried movement up ahead.
“I fear he has heard us,” Pons whispered.
He moved forward again, and abruptly stood up. I crowded out to join him. We stood on the right-of-way of the abandoned Nunhead-Crystal Palace Line. The rails were still in place, and the railbed was clearly the source of the cinder Pons had produced for my edification. Far ahead of us on the line someone was running.
“No matter,” said Pons. “There is only one way for him to go. He could hardly risk going out to where the nearby Victoria line passes. He must go out by way of the Lordship Lane entrance.”
We pressed forward, and soon the light revealed a niche hollowed out of the wall. It contained bedding, a half-eaten loaf of bread, candles, a lantern, books. Outside the opening were dozens of empty wine bottles, and several that had contained brandy.
Pons bent to examine the bedding.
“Just as I thought,” he said, straightening up. “This has not been here very long — certainly not longer than two months.”
“The time since the younger Brensham’s death,” I cried.
“You advance, Parker, you advance, indeed!”
“Then he and Narth were in it together!”
“Of necessity,” said Pons. “Come.”
He ran rapidly down the line, I after him.
Up ahead there was a sudden burst of shouting. “Aha!” cried Pons. “They have him!”
After minutes of hard running, we burst out of the tunnel at the entrance where Inspector Jamison and Constable Meeker waited — the constable manacled to a wild-looking old man, whose fierce glare was indeed alarming. Greying hair stood out from his head, and his unkempt beard completed a frame of hair around a grimy face out of which blazed two eyes fiery with rage.
“He gave us quite a struggle, Pons,” said Jamison, still breathing heavily.
“Capital! Capital!” cried Pons, rubbing his hands together delightedly. “Gentlemen, let me introduce you to as wily an old scoundrel as we’ve had the pleasure of meeting in a long time. Captain Jason Brensham, swindler of insurance companies and, I regret to say, murderer.”
“Narth!” exclaimed Jamison.
“Ah, Jamison, you had your hands on him. But I fear you lost him when you gave him to Spilsbury.”
“The problem was elementary enough,” said Pons, as he filled his pipe with the abominable shag he habitually smoked and leaned up against the mantel in our quarters later that night. “Mrs. Ashcroft told us everything essential to its solution, and Harwell only confirmed it. The unsolved question was the identity of the victim, and the files of the national press gave me a presumptive answer to that in the disappearance of Ian Narth, a man of similar build and age to Captain Brensham.
“Of course, it was manifest at the outset that this motiveless spectre was chancing discovery for survival. It was not Jenkins but the Captain who was raiding the food and liquor stocks at his house. The cave, of course, was never intended as a permanent hiding place, but only as a refuge to seek when strangers came to the house, or whenever his nephew had some of his friends in. He lived in the house; he had always been reclusive, and he changed his way of life but little. His nephew, you will recall Harwell’s telling us, continued to subscribe to his magazines and buy the books he wanted, apparently for himself, but obviously for his uncle. The bedding and supplies were obviously moved into the tunnel after the younger Brensham’s death.
“The manner and place of the ghost’s appearance suggested the opening in the wall. The cinder in the carpet cried aloud of the abandoned Nunhead-Crystal Place Line which the maps I studied in the British Museum confirmed ran almost under the house. The Captain actually had more freedom than most dead men, for he could wander out along the line by night, if he wished.
“Harwell clearly set forth the motive. The Captain had sold off everything he had to enable him to continue his way of living. He needed money. His insurance policies promised to supply it. He and his nephew together hatched up the plot. Narth was picked as victim, probably out of a circle of acquaintances because, as newspaper, descriptions made clear, he had a certain resemblance to the Captain and was, like him, a retired seaman with somewhat parallel tastes.
“They waited until the auspicious occasion when Dr. Weston, who knew the Captain too well to* be taken in, was off on a prolonged holiday, lured Narth to the house, killed him with a lethal dose of arsenic, after which they cleaned up the place to eliminate all external trace of poison and its effects, and called in Dr. Weston’s locum to witness the dying man’s last minutes. The Captain was by this time in his cave, and the young doctor took Howard Brensham’s word for the symptoms and signed the death certificate, after which the Brenshams had ample funds on which to live as the Captain liked.”
“And how close they came to getting away with it!” I cried.
“Indeed! Howard Brensham’s unforeseen death — ironically, of a genuine heart attack — was the little detail they had never dreamed of. On similar turns of fate empires have fallen!”