"And my salvation," Copplestone added.
"There," said Monsieur Dupont, "it passes to you to enlighten me."
"First," returned Copplestone, "I should like to know what caused you to be so positive, after being in my house only two or three hours, that there was a secret in it."
"My instinct for the mysterious is seldom at fault," said Monsieur Dupont. "Have you not observed how, by their characters, their habits, and their desires, human beings draw to themselves certain events and conditions of life? And it is equally true that houses draw to themselves certain contents and certain kinds of inhabitants. If a house is particularly adapted to contain a secret, in the course of time will certainly contain one. By a few strokes of his pencil an architect can condemn a house to become the scene of a murder, as surely as he can make it a convenient or inconvenient dwelling. Your house was constructed to hide a secret. And I was not only sure that it did hide one, but that it hid one which was in some way connected with the crime in the garden."
"I have had some experience of that instinct of yours," the inspector remarked, with a somewhat rueful smile.
"Well," said Copplestone, "instinct or no instinct, it certainly did hide a secret, and that secret was that Oscar Winslowe lived in it—if his condition could be called living. For the last five years he had been practically a helpless imbecile. He seldom uttered a sound beyond a gibber, and hardly seemed to be conscious. He was suffering the natural consequences of his vices. He had been gradually reaching that condition since nature had dealt him her first stroke of vengeance more than thirty years ago. One by one his faculties had rotted. He was a living mass of decay."
"It was a sure thing," the doctor said. "Such a condition was bound to come. I prophesied it to his face when I first knew him."
"That was the secret of my house," Copplestone proceeded. "My own secret was that I believed myself to be his son—the inheritor of the curse that really belonged to Tranter. And the horror of it, the helplessness, the constant contemplation of the awful state of the man I knew as my father, and the morbid certainty that sooner or later I must come to the same state, actually drove me to the madness that was not really in me at all."
"But how had you come to believe yourself to be his son?" the inspector asked.
"That was the last of Winslowe's diabolical acts. He inherited a large fortune on condition that a child of his, to whom it could succeed, was alive at the time of the testator's death. He did not know anything of his own child, and did not want to. He was afraid that if he made public inquiries for it, he might learn publicly that it was dead, and lose his claim. Also, he was afraid of other complications and exposures."