“I owe him an apology. Perhaps I owe a good many people an apology.”
“None will ever be asked for,” said Malone. “These people are not made that way.”
“It is the second case which I would explain.” The Professor fidgeted uneasily in his chair. “It is a matter of great privacy—one to which I have never alluded, and which no one on earth could have known. Since you heard so much you may as well hear all.
“It happened when I was a young physician, and it is not too much to say that it cast a cloud over my life—a cloud which has only been raised to-night. Others may try to explain what has occurred by telepathy, by subconscious mind action, by what they will, but I cannot doubt—it is impossible to doubt—that a message has come to me from the dead.
“There was a new drug under discussion at that time. It is useless to enter into details which you would be incapable of appreciating. Suffice it that it was of the datura family which supplies deadly poisons as well as powerful medicines. I had received one of the earliest specimens, and I desired my name to be associated with the first exploration of its properties. I gave it to two men, Ware and Aldridge. I gave it in what I thought was a safe dose. They were patients, you understand, in my ward in a public hospital. Both were found dead in the morning.
“I had given it secretly. None knew of it. There was no scandal for they were both very ill, and their death seemed natural. But in my own heart I had fears. I believed that I had killed them. It has always been a dark background to my life. You heard yourselves to-night that it was from the disease, and not from the drug that they died.”
“Poor Dad!” whispered Enid, patting the great hirsute hand. “Poor Dad! What you must have suffered!”
Challenger was too proud a man to stand pity, even from his own daughter. He pulled away his hand.
“I worked for science,” he said. “Science must take risks. I do not know that I am to blame. And yet—and yet—my heart is very light to-night.”