"No; Frank Errington was not committed for trial on the capital charge," said the man in the corner with one of his sardonic smiles, "thanks to the cleverness of Sir Arthur Inglewood, his lawyer. He absolutely denied his identity with the man in the tweed suit, and swore he had not seen Mrs. Hazeldene since eleven o'clock in the morning of that fatal day. There was no proof that he had; moreover, according to Mr. Campbell's opinion, the man in the tweed suit was in all probability not the murderer. Common sense would not admit that a woman could have a deadly poison injected into her without her knowledge, while chatting pleasantly to her murderer.
"Mr. Errington lives abroad now. He is about to marry. I don't think any of his real friends for a moment believed that he committed the dastardly crime. The police think they know better. They do know this much, that it could not have been a case of suicide, that if the man who undoubtedly travelled with Mrs. Hazeldene on that fatal afternoon had no crime upon his conscience he would long ago have come forward and thrown what light he could upon the mystery.
"As to who that man was, the police in their blindness have not the faintest doubt. Under the unshakable belief that Errington is guilty they have spent the last few months in unceasing labour to try and find further and stronger proofs of his guilt. But they won't find them, because there are none. There are no positive proofs against the actual murderer, for he was one of those clever blackguards who think of everything, foresee every eventuality, who know human nature well, and can foretell exactly what evidence will be brought against them, and act accordingly.
"This blackguard from the first kept the figure, the personality, of Frank Errington before his mind. Frank Errington was the dust which the scoundrel threw metaphorically in the eyes of the police, and you must admit that he succeeded in blinding them—to the extent even of making them entirely forget the one simple little sentence, overheard by Mr. Andrew Campbell, and which was, of course, the clue to the whole thing—the only slip the cunning rogue made—'Au revoir! Don't be late to-night.' Mrs. Hazeldene was going that night to the opera with her husband—
"You are astonished?" he added with a shrug of the shoulders, "you do not see the tragedy yet, as I have seen it before me all along. The frivolous young wife, the flirtation with the friend?—all a blind, all pretence. I took the trouble which the police should have taken immediately, of finding out something about the finances of the Hazeldene ménage. Money is in nine cases out of ten the keynote to a crime.
"I found that the will of Mary Beatrice Hazeldene had been proved by the husband, her sole executor, the estate being sworn at £15,000. I found out, moreover, that Mr. Edward Sholto Hazeldene was a poor shipper's clerk when he married the daughter of a wealthy builder in Kensington—and then I made note of the fact that the disconsolate widower had allowed his beard to grow since the death of his wife.
"There's no doubt that he was a clever rogue," added the strange creature, leaning excitedly over the table, and peering into Polly's face. "Do you know how that deadly poison was injected into the poor woman's system? By the simplest of all means, one known to every scoundrel in Southern Europe. A ring—yes! a ring, which has a tiny hollow needle capable of holding a sufficient quantity of prussic acid to have killed two persons instead of one. The man in the tweed suit shook hands with his fair companion—probably she hardly felt the prick, not sufficiently in any case to make her utter a scream. And, mind you, the scoundrel had every facility, through his friendship with Mr. Errington, of procuring what poison he required, not to mention his friend's visiting card. We cannot gauge how many months ago he began to try and copy Frank Errington in his style of dress, the cut of his moustache, his general appearance, making the change probably so gradual, that no one in his own entourage would notice it. He selected for his model a man his own height and build, with the same coloured hair."
"But there was the terrible risk of being identified by his fellow-traveller in the Underground," suggested Polly.
"Yes, there certainly was that risk; he chose to take it, and he was wise. He reckoned that several days would in any case elapse before that person, who, by the way, was a business man absorbed in his newspaper, would actually see him again. The great secret of successful crime is to study human nature," added the man in the corner, as he began looking for his hat and coat. "Edward Hazeldene knew it well."
"But the ring?"