Leaning forward in his seat, the driver lashed his horses into a gallop. The carriage had barely halted at the railroad station, when a woman leaped out. She was closely veiled; but her slender figure revealed the fact that she was little more than a girl. She paused just long enough to hand the driver a bill, then hurried to a train.

When the conductor passed through the cars he found the slender young woman sitting in one of the day coaches. She paid her fare in cash through to Albany, and made inquiry about accommodations in the sleeping car. He volunteered to arrange the matter for her; and so it came to pass that half an hour after she had boarded the train she was ushered into the more exclusive rear car.

“We have only one upper berth,” the conductor there apologized.

“Oh, well, it doesn’t really matter,” she remarked listlessly, and was shown to a seat.

Then for the first time she raised her veil. Her pretty face was still flushed from the excitement of catching the train; but a haunting, furtive fear mingled with a shade of sorrow in the shadowy, dark eyes, and the red lips expressed a sullen defiance. For a long time she sat moodily thoughtful, staring out of the window; then the growing dusk obliterated the flying landscape, and the porter came through to light the lamps.

After awhile the door of the drawing room compartment at one end of the car opened, and a young woman glanced out. It might have been idle curiosity which caused her to scrutinize the lounging passengers; but her eyes paused, with a flash of recognition, on the crisp, brown hair of the slender young woman just half a dozen seats ahead, and she went forward.

“Why, Julia!” she exclaimed. “I hadn’t the faintest idea you were on the train!”

First there came an embarrassed surprise into the face of the slender young woman; but it was instantly followed by an expression of relief.

“Oh, Mary! How you startled me!”

There was a little interchange of greetings, which ended by Miss Mary Langham leading Miss Julia Farrar back into the snug little drawing room. They had been classmates at Vassar, these two, and there were a thousand things to talk about; yet in the manner of each was a certain restraint, a vague, indefinable reserve. As a breaking point of a sudden silence which fell between them, Miss Farrar mentioned the upper berth that she had been given.

“Well, don’t worry about that a moment, my dear,” urged Miss Langham cheerfully. “I have this whole big compartment, and there are two lower berths. You shall take one, and I’ll take the other.” There was silence for a moment. “But, my dear girl, where are you going?”

“I’m going to Albany — now,” was the reply.

“Right on the eve of your —”

“I’m not going to marry Mr. Devore!” interrupted Miss Farrar with quick passion.

Miss Langham lifted her arched brows in astonishment. “Why, Julia, you amaze me!” she exclaimed.

“I’m running away from him now,” she went on.

Miss Langham stared at her blankly for an instant. Defiance flamed in Miss Farrar’s face; there were tense little lines about the mouth, and the lips were pressed sternly together. But at last some glimmer of comprehension seemed to reach Miss Langham, and with it came an expression which might almost have been of relief. With a quick movement she seized Miss Farrar’s hand.

“I think I understand, dear,” she said sympathetically at last. “Under all circumstances, I don’t know that I can blame you either. Mr. Devore must know that you don’t love him.”

“Well, if he doesn’t, it isn’t because I haven’t told him so, goodness knows!” replied Miss Farrar.

Miss Langham laughed lightly, and her eyes reflected some strange, new born light, a glimmer of satisfaction.

“Poor fellow!” she mused. “And he is so devoted!”

“I don’t want his devotion!” blazed Miss Farrar. “The mere sight of him is intolerable to me. It’s all just like — like I was being sold to him. It’s perfectly hideous, and I won’t — I won’t — I won’t!”

Defiance melted into tears of anger and mortification, and Miss Farrar lay against Miss Langham’s shoulder while her slender figure was shaken by a storm of sobs. Miss Langham stroked the crisp, brown hair back from the white temples, and continued to stare dreamily out of the window.

“Even my father and mother and brother conspired with him against me,” Miss Farrar sobbed after a time. “They insisted on the marriage from the first, merely because Mr. Devore happens to be wealthy. I don’t know why I ever agreed, unless it was just desperation. I detest the man, and yet the members of my own family, knowing that, could only think of the brilliant match, the money, and social position which marriage would bring.”

“Tomorrow it was to have been,” mused Miss Langham vacantly.

“Yes, tomorrow. For weeks and weeks it has been a nightmare to me, and last night, somehow, I seemed to go all to pieces. The sight of the wedding gown made me perfectly furious. All today I thought of it, and thought of it, until my head seemed bursting. Then late this afternoon I could stand it no longer; so I— I ran away. I suppose it’s horrid of me, and I know my father and mother will never forgive me for the scandal it will cause; but I don’t care. They’ve made me almost hate them. I’m going to my aunt’s in Albany and remain there for a few days. Of course, my father will be furious, and will try to force me to return; but she’s a dear loyal soul and won’t let them take me away. Then I shall decide about the future.”

“I can’t imagine a worse fate than marriage with a man whom you don’t love,” said Miss Langham after a pause. “I don’t blame you at all. But remember, my dear, in giving up your family you will have to look out for yourself — perhaps earn your own living?”

“I don’t care,” continued Miss Farrar passionately. “I have fifty or sixty dollars now, and before that is gone surely I can get a place as teacher, or governess, or something. I will do something.”

“And I have no doubt that everything will come right,” Miss Langham assured her. She raised the tear stained face between her hands and printed a kiss on each damp cheek. “And now, my dear, you need repose. Lie down and rest for awhile.”

With the obedience of a child Miss Farrar lay across the berth, and after awhile, with Miss Langham’s hand clasped between her own, closed her red, swollen eyes in sleep.

It was perhaps half an hour later that Miss Langham pressed her call button beside the door. A porter appeared.

“What is the next stop?” she inquired.

“East Newlands,” was the reply.

“Can I send a telegram from there?”

“Yes, ma’am.”

Miss Langham gently detached her fingers from the clinging clasp of the sleeping girl, and scribbled a telegram on a blank which the porter offered. It was addressed to J. Charles Wingate, in a small city, just beyond Albany, and said:

Have changed my mind. This is irrevocable. M.

When the train pulled into Albany the following morning Miss Julia Farrar was found dead in her berth, fully dressed, except for her hat. A thirty-two caliber bullet had entered her body just below the left shoulder. Miss Langham herself gave the alarm. When physicians came they agreed that Miss Farrar had been dead for at least two hours.

Professor Augustus S. F. X. Van Dusen — The Thinking Machine — absorbed, digested, and assimilated all the known facts in the problem of the private compartment. Instantly that singular, penetrating brain beneath the mop of tangled, straw yellow hair was alive with questions.

“Who is Miss Langham?” was the first query.

“She is the daughter of Daniel Eustace Langham, president of a national bank in his home city,” replied Hutchinson Hatch, reporter. “She and Miss Farrar were classmates in Vassar, and met by accident on the train.”

“Do you know they met by accident?”

“It seems to have been by accident,” the reporter amended. “As a matter of fact, Miss Langham was on the train first — in fact, had engaged the drawing room compartment a couple of days ahead.”

“Does she know — Miss Langham, I mean — know Devore?”

“Very well indeed,” responded the reporter. “A couple of years ago he was rather assiduous in his attentions to her. That was before Devore met Miss Farrar.”

The Thinking Machine turned suddenly in his chair and squinted into the eyes of the newspaper man. Faint corrugations in the domelike brow were swept away.

“Oh!” he exclaimed. “An old love affair! How did it come to be broken off?”

“I imagine it was Devore who broke it off,” replied Hatch. “When he met Miss Farrar it resulted in a quick transfer of attentions. As a matter of fact, he doesn’t seem to be a very pleasant sort of person, anyway — spoiled son and sole heir of a man worth millions. You know what that means.”

“And where was Miss Langham going at the time of the tragedy?” inquired the scientist.

“To visit some friends just beyond Albany.”

For a long time The Thinking Machine was silent, while Hatch turned over those vague impressions which the scientist’s manner and words had created.

“That seems to simplify the matter somewhat,” mused The Thinking Machine at last.

“You don’t mean,” blurted Hatch quickly —“you don’t mean that Miss Langham could have had anything to do with Miss Farrar’s death?”

“Why not?” demanded The Thinking Machine coldly.

“But her social position, her wealth, everything, would seem to remove her beyond the range of suspicion,” Hatch protested.

The Thinking Machine regarded him with frank disapproval. “Two and two always make four, Mr. Hatch,” he said shortly. “We have here a motive for the crime — jealousy — and practically exclusive opportunity. Social position and wealth do not deter criminals; they only make them more cunning. In this case two and two make four so obviously that I am surprised Miss Langham wasn’t arrested immediately. Where is she now, by the way?”

“With her father and mother at the Hotel Bellevoir in town here,” Hatch responded. “Immediately after the tragedy was reported she returned here, and her father and mother joined her. She is now suffering from shock, and inaccessible — at least to reporters.”

“Any physician?”

“Dr. Barrow and Dr. Curtis are attending her.”

“I may call on her in person,” remarked The Thinking Machine. “And now about this man Devore? Have you seen him?”

“He was the first man the police wanted to see,” explained the reporter. “They have already made him account for his every move on the night of the murder. Of course, a motive in his case would be obvious — anger, revenge, jealousy, anything.”

“And where was he between, say, midnight and breakfast that night?”

“He says he was asleep at home.”

“He says!” snapped The Thinking Machine abruptly. “Don’t you know?”

“Not of my knowledge.”

“Well, find out!” was the curt instruction. “That isn’t one of the things that we can be at all uncertain about.”

Hatch opened his eyes again. Here were two lines of investigation laid out by the scientist, either one of which might, if pursued to a logical conclusion, convict a person of wealth and position of a terrible crime.

“And Miss Farrar’s family?” continued The Thinking Machine mercilessly. “Where were her father and brother that night?”

“Surely you can’t believe that —”

“I never believe anything, Mr. Hatch, until I know it. I merely wanted to know where they were; for on that side too it is possible to conceive a motive for Miss Farrar’s death.”

“There has been no inquiry in that direction at all,” explained the bewildered reporter. “I’ll begin one.”

Then for a time The Thinking Machine sat with fingertips pressed idly together, squinting blankly at the ceiling.

“While a motive is never absolutely essential to the solution of any criminal problem,” he observed after awhile, “it will frequently indicate a line of investigation.............