Every eye was turned on Reid. He sat as if fascinated, staring into the upward turned face of the scientist.
"There we had a girl – presumably Miss Melrose – dead, by a knife owned by Mr. Curtis, last in the possession of Mr. Reid. Mr. Hatch had previously told me that the medical examiner said the wound which killed the girl came from her right, in a general direction. Therefore here was a possibility that Mr. Reid did it in the automobile – a possibility, I say.
"I asked Mr. Curtis why he tried to recover the knife from Dr. Leonard. He stammered and faltered, but really it was because, having recognized the knife, he was afraid the crime would come home to him. Mr. Curtis denied flatly that the knife was his, and in denying told me that it was. It was not Mr. Reid's I was assured. Mr. Curtis also told me of his love for Miss Melrose, but there was nothing there, as it appeared, strong enough to suggest a motive for murder. He mentioned you, Mr. MacLean, then.
"Then Mr. Curtis named Miss Dow as one whose hand had been sought by Mr. Reid. Mr. Hatch told me this girl – Miss Dow – had eloped the night before with Morgan Mason from Monarch Inn – or, to be exact, that her family had received a letter from her stating that she was eloping; that Mason had taken out a marriage license. Remember this was the girl that Reid was in love with; it was singular that there should have been a Monarch Inn end to that elopement as well as to this tragedy.
"This meant nothing as bearing on the abstract problem before me until Mr. Curtis described Miss Melrose as having golden hair. With another minor scrap of information Mr. Hatch again opened up vast possibilities by stating that the medical examiner, a careful man, had said Miss Melrose had dark hair. I asked him if he had seen the body; he had not. But the medical examiner told him that. Instantly in my mind the question was aroused: Was it Miss Melrose who was killed? This was merely a possibility; it still had no great weight with me.
"I asked Mr. Curtis as to the circumstances which caused his collapse in Winter Street. He explained it was because he had seen a woman whom he would have sworn was Miss Melrose if he had not known that she was dead. This, following the dark hair and blonde hair puzzle, instantly caused this point to stand forth sharply in my mind. Was Miss Melrose dead at all? I had good reason then to believe that she was not.
"Previously, with the idea of fixing for all time the ownership of the knife – yet knowing in my own mind it was Mr. Curtis' – I had sent for Mr. Reid. I told him Mr. Curtis had said it was his knife. Mr. Reid fell into the trap and did the very thing I expected. He declared angrily the knife was Mr. Curtis', thinking Curtis had tried to saddle the crime on him. Then I turned Mr. Curtis over to the police. When he was locked up I was reasonably certain that he did not commit any crime, because I had traced the knife from him to Mr. Reid."
There was a glitter in Reid's eyes now. It was not fear, only a nervous battle to restrain himself. The Thinking Machine went on:
"I saw the body of the dead woman – indeed, assisted at her autopsy. She was a pronounced brunette – Miss Melrose was a blonde. The mistake in identity was not an impossible one in view of the fact that each wore a mask and had her hair tied up under a veil. That woman was stabbed from the right – still a possibility of suicide."
"Who was the woman?" demanded Curtis. He seemed utterly unable to control himself longer.
"Miss Elizabeth Dow, who was supposed to have eloped with Morgan Mason," was the quiet reply.
Instant amazement was reflected on every face save Reid's, and again every eye was turned to him. Miss Dow's maid burst into tears.
"Mr. Reid knew who the woman was all the time," said The Thinking Machine. "Knowing then that Miss Dow was the dead woman – this belief being confirmed by a monogram gold belt buckle, 'E. D., on the body – I proceeded to find out all I could in this direction. The waiters had seen Mr. Reid in the inn; had seen him talking to a masked and veiled lady who had been waiting for nearly an hour; had seen him go into a room with her, but had not seen them leave the inn. Mr. Reid had recognized the lady – not she him. How? By a glimpse of the monogram belt buckle which he knew because he probably gave it to her."
"He did," interposed Hatch.
"I did," said Reid, calmly. It was the first time he had spoken.
"Now, Mr. Reid went into the room and closed the door, carrying with him Mr. Curtis' knife," went on The Thinking Machine. "I can't tell you from personal observation what happened in that room, but I know. Mr. Reid learned in some way that Miss Dow was going to elope; he learned that she had been waiting long past the time when Mason was due there; that she believed he had humiliated her by giving up the idea at the last minute. Being in a highly nervous condition, she lost faith in Mason and in herself, and perhaps mentioned suicide?"
"She did," said Reid, calmly.
"Go on, Mr. Reid," suggested The Thinking Machine.
"I believed, too, that Mason had changed his mind," the young man continued, with steady voice. "I pleaded with Miss Dow to give up the idea of eloping, because, remember, I loved her, too. She finally consented to go on with our party, as her automobile had gone. We came out of the inn together. When we reached the automobile – The Green Dragon, I mean – I saw Miss Melrose getting into Mr. MacLean's automobile, which had come up meanwhile. Instantly I saw, or imagined, the circumstances, and said nothing to Miss Dow about it, particularly as Mr. MacLean's car dashed away at full speed.
"Now, in taking Miss Dow to The Green Dragon it had been my purpose to introduce her to Miss Melrose. She knew Mr. Curtis. When I saw Miss Melrose was gone I knew Curtis would wonder why. I couldn't explain, because every moment I was afraid Mason would appear to claim Miss Dow and I was anxious to get her as far away as possible. Therefore I requested her not to speak until we reached the next inn, and there I would explain to Curtis.
"Somewhere between the Monarch Inn and the inn we had started for Miss Dow changed her mind; probably was overcome by the humiliation of her position, and she used the knife. She had seen me take the knife from my pocket and throw it into the tool kit on the floor beside her. It was comparatively a trifling matter for her to stoop and pick it up, almost from under her feet, and-"
"Under all these circumstances, as stated by Mr. Reid," interrupted The Thinking Machine, "we understand why, after he found the girl dead, he didn't tell all the truth, even to Curtis. Any jury on earth would have convicted him of murder on circumstantial evidence. Then, when he saw Miss Dow dead, mistaken for Miss Melrose, he could not correct the impression without giving himself away. He was forced to silence.
"I realized these things – not in exact detail as Mr. Reid has told them, but in a general way – after my talk with the waiters. Then I set out to find out why Mason had not appeared. It was possibly due to accident. On a chance entirely I asked the man in charge of the gasoline tank at the Monarch if he had heard of an accident nearby on the night of the tragedy. He had.
"With Mr. Hatch I found the injured man. A monogram, 'M.M.,' on his watch, told me it was Morgan Mason. Mr. Mason had a serious accident and still lies unconscious. He was going to meet Miss Dow when this happened. He had two railroad tickets to New York – for himself and bride – in his pocket."
Reid still sat staring at The Thinking Machine, waiting. The others were awed into silence by the story of the tragedy.
"Having located both Mason and Miss Dow to my satisfaction, I then sought to find what had become of Miss Melrose. Mr. Reid could have told me this, but he wouldn't have, because it would have turned the light on the very thing which he was trying to keep hidden. With Miss Melrose alive, it was perfectly possible that Curtis had seen her in the Winter Street store.