Unexpectedly the little wired wireless instrument before us began to buzz. Quickly Kennedy seized a pencil and wrote as the message that no hand of man could interfere with was flashed back to us.

"It is for you, Walter, from the Star," he said, simply handing me what he had written on the back of an old envelope.

I read, almost afraid to read:

Robbery story killed. Black type across page-head last edition, "Treasure-train safe!"

McGRATH.

"Show it to Miss Euston," Craig added, simply, gathering up his wired wireless set, just as the crew from the train behind us ran up. "She may like to know that she has saved her father from himself through misunderstanding her lover."

I thought Maude Euston would faint as she clutched the message. Lane caught her as she reeled backward.

"Rodman--can you--forgive me?" she murmured, simply, yielding to him and looking up into his face.

II

THE TRUTH DETECTOR

"You haven't heard--no one outside has heard--of the strange illness and the robbery of my employer, Mr. Mansfield--'Diamond Jack'

Mansfield, you know."

Our visitor was a slight, very pretty, but extremely nervous girl, who had given us a card bearing the name Miss Helen Grey.

"Illness--robbery?" repeated Kennedy, at once interested and turning a quick glance at me.

I shrugged my shoulders in the negative. Neither the Star nor any of the other papers had had a word about it.

"Why, what's the trouble?" he continued to Miss Grey.

"You see," she explained, hurrying on, "I'm Mr. Mansfield's private secretary, and--oh, Professor Kennedy, I don't know, but I'm afraid it is a case for a detective rather than a doctor." She paused a moment and leaned forward nearer to us. "I think he has been poisoned!"

The words themselves were startling enough without the evident perturbation of the girl. Whatever one might think, there was no doubt that she firmly believed what she professed to fear. More than that, I fancied I detected a deeper feeling in her tone than merely loyalty to her employer.

"Diamond Jack" Mansfield was known in Wall Street as a successful promoter, on the White Way as an a.s.siduous first-nighter, in the sporting fraternity as a keen plunger. But of all his hobbies, none had gained him more notoriety than his veritable pa.s.sion for collecting diamonds.

He came by his sobriquet honestly. I remembered once having seen him, and he was, in fact, a walking De Beers mine. For his personal adornment, more than a million dollars' worth of gems did relay duty.

He had scores of sets, every one of them fit for a king of diamonds. It was a curious hobby for a great, strong man, yet he was not alone in his love of and sheer affection for things beautiful. Not love of display or desire to attract notice to himself had prompted him to collect diamonds, but the mere pleasure of owning them, of a.s.sociating with them. It was a hobby.

It was not strange, therefore, to suspect that Mansfield might, after all, have been the victim of some kind of attack. He went about with perfect freedom, in spite of the knowledge that crooks must have possessed about his h.o.a.rd.

"What makes you think he has been poisoned?" asked Kennedy, betraying no show of doubt that Miss Grey might be right.

"Oh, it's so strange, so sudden!" she murmured.

"But how do you think it could have happened?" he persisted.

"It must have been at the little supper-party he gave at his apartment last night," she answered, thoughtfully, then added, more slowly, "and yet, it was not until this morning, eight or ten hours after the party, that he became ill." She shuddered. "Paroxysms of nausea, followed by stupor and such terrible prostration. His valet discovered him and sent for Doctor Murray--and then for me."

"How about the robbery?" prompted Kennedy, as it became evident that it was Mansfield's physical condition more than anything else that was on Miss Grey's mind.

"Oh yes"--she recalled herself--"I suppose you know something of his gems? Most people do." Kennedy nodded. "He usually keeps them in a safe-deposit vault downtown, from which he will get whatever set he feels like wearing. Last night it was the one he calls his sporting-set that he wore, by far the finest. It cost over a hundred thousand dollars, and is one of the most curious of all the studies in personal adornment that he owns. All the stones are of the purest blue-white and the set is entirely based on platinum.

"But what makes it most remarkable is that it contains the famous M-1273, as he calls it. The M stands for Mansfield, and the figures represent the number of stones he had purchased up to the time that he acquired this huge one."

"How could they have been taken, do you think?" ventured Kennedy. Miss Grey shook her head doubtfully.

"I think the wall safe must have been opened somehow," she returned.

Kennedy mechanically wrote the number, M-1273, on a piece of paper.

"It has a weird history," she went on, observing what he had written, "and this mammoth blue-white diamond in the ring is as blue as the famous Hope diamond that has brought misfortune through half the world.

This stone, they say, was pried from the mouth of a dying negro in South Africa. He had tried to smuggle it from the mine, and when he was caught cursed the gem and every one who ever should own it. One owner in Amsterdam failed; another in Antwerp committed suicide; a Russian n.o.bleman was banished to Siberia, and another went bankrupt and lost his home and family. Now here it is in Mr. Mansfield's life. I--I hate it!" I could not tell whether it was the superst.i.tion or the recent events themselves which weighed most in her mind, but, at any rate, she resumed, somewhat bitterly, a moment later: "M-1273! M is the thirteenth letter of the alphabet, and 1, 2, 7, 3 add up to thirteen.

The first and last numbers make thirteen, and John Mansfield has thirteen letters in his name. I wish he had never worn the thing--never bought it!"

The more I listened to her the more impressed I was with the fact that there was something more here than the feeling of a private secretary.

"Who were in the supper-party?" asked Kennedy.

"He gave it for Madeline Hargrave--the pretty little actress, you know, who took New York by storm last season in 'The Sport' and is booked, next week, to appear in the new show, 'The Astor Cup.'"

Miss Grey said it, I thought, with a sort of wistful envy. Mansfield's gay little bohemian gatherings were well known. Though he was not young, he was still somewhat of a Lothario.

"Who else was there?" asked Kennedy.

"Then there was Mina Leitch, a member of Miss Hargrave's new company,"

she went on. "Another was Fleming Lewis, the Wall Street broker. Doctor Murray and myself completed the party."

"Doctor Murray is his personal physician?" ventured Craig.

"Yes. You know when Mr. Mansfield's stomach went back on him last year it was Doctor Murray who really cured him."

Kennedy nodded.

"Might this present trouble be a recurrence of the old trouble?"

She shook her head. "No; this is entirely different. Oh, I wish that you could go with me and see him!" she pleaded.

"I will," agreed Kennedy.

A moment later we were speeding in a taxicab over to the apartment.

"Really," she remarked, nervously, "I feel lost with Mr. Mansfield so ill. He has so many interests downtown that require constant attention that just the loss of time means a great deal. Of course, I understand many of them--but, you know, a private secretary can't conduct a man's business. And just now, when I came up from the office, I couldn't believe that he was too ill to care about things until I actually saw him."

We entered the apartment. A mere glance about showed that; even though Mansfield's hobby was diamonds, he was no mean collector of other articles of beauty. In the big living-room, which was almost like a studio, we met a tall, spare, polished-mannered man, whom I quickly recognized as Doctor Murray.