"You see," he digressed, "to get the two the same shade I have to dilute the first by the second. Now, the dialyzers are not permeable to alb.u.min. Therefore the violet color indicates that the blood serum in this case contains ferments which the body is making to split up some foreign substance in the blood, such as I suspected and obtained from the hospital. The test is positive. Mr. Seabury, how long have you felt as you say that you do?"

"Several weeks," the man returned weakly.

"That is fortunate," cried Kennedy, "fortunate that it has not been several months."

He paused, then added the startling statement, "Mr. Seabury, I can find no evidence here of poison. As a matter of fact, the wonderful Abderhalden test shows me that you have one of the most common forms of internal disease that occur for the most part in persons at or after middle life, about the age of fifty, more common in men than in women--a disease which taken in time, as it has been revealed by this wonderful test, may be cured and you may be saved--an incipient cancer of the stomach."

Kennedy paused a moment and listened. I fancied I heard someone in the hall. But he went on, "The person whom you suspect of poisoning you--"

There came a suppressed scream from the door, as it was flung open and Agatha Seabury stood there, staring with fixed, set eyes at Kennedy, then at her husband. Mechanically I looked at my watch. It was precisely eight. Kennedy had evidently prolonged the test for a purpose.

"The person whom you suspected," he repeated firmly, "is innocent!"

A moment Agatha stood there, then as the thing dawned on her, she uttered one cry, "Judson!"

She reeled as Kennedy with a quick step or two caught her.

Seabury himself seemed dazed.

"And I have--" he e.j.a.c.u.l.a.t.ed, then stopped.

Kennedy raised his hand. "Just a moment, please," he interrupted, as he placed Mrs. Seabury in a chair, then glanced hastily at his watch.

She saw the motion and seemed suddenly to realize that it was nearing the time for Sherburne to call up. With a mighty effort she seemed to grip herself. She had just been shocked to know that she was charged unjustly. But had she been cleared from one peril only to fall a victim to another--the one she already feared? Was Sherburne to escape, after all, and ruin her?

The telephone tinkled insistently. Kennedy seized the receiver.

"Who is it?" we heard him ask. "Mr. Sherburne--oh yes."

Mrs. Seabury paled at the name. I saw her shoot a covert glance at her husband, and was relieved to see that his face betrayed as yet no recognition of the name. She turned and listened to Kennedy, straining her ears to catch every syllable and interpret every sc.r.a.p of the one-sided conversation.

Quickly Craig had jammed the receiver down on a little metal base which we had not noticed near the instrument. Three p.r.o.ngs reaching upward from the base engaged the receiver tightly, fitting closely about it.

Then he took up a watch-case receiver to listen through, in place of the regular receiver.

"Sherburne, you say?" he repeated. "H. Morgan Sherburne?"

Apparently the voice at the other end of the wire replied rather peevishly, for Kennedy endeavored to smooth over the delay. We waited impatiently as he reiterated the name. Why was he so careful about it?

The moments were speeding fast and Mrs. Seabury found the suspense terrific.

"Must pay--we'll never get anything on you?" Craig repeated after a few moments further parley. "Very well. I am commissioned to meet you there in ten minutes and settle the thing up on those terms," he concluded as he clapped the regular receiver back on its hook with a hasty good-by and faced us triumphantly.

"The deuce I won't get anything. I've got it!" he exclaimed.

Judson Seabury was too stunned by the revelation that he had a cancer to follow clearly the maze of events.

"That," cried Kennedy, rising quickly, "is what is known as the telescribe--a new invention of Edison that records on a specially prepared phonograph cylinder all that is said--both ways--over a telephone wire. Come!"

Ten minutes later, in a cab that had been waiting at the door, we pulled up at the Vanderveer.

Without a word, leaving Judson Seabury and his wife in the waiting cab, Craig sprang out, followed by me, as he signaled.

There was Sherburne, brazen and insolent, in the cafe as we entered, from a rear door, and came upon him before he knew it, our friend, Dunn, whom we had met in the lobby, hovering concealed outside, ready to come to our a.s.sistance.

In a moment Kennedy was at Sherburne's elbow, pinching it in the manner familiar to international crooks.

"Will you tell me what your precise business is in this hotel?" shot out Craig before Sherburne could recover from his surprise.

Sherburne flushed and flared--then became pale with rage.

"None of your d.a.m.ned insolence!" he ground out, then paused, cutting the next remark short as he gritted, "What do you mean? Shall I send a wax impression of that key--"

Kennedy had quickly flashed the cylinder of the telescribe before his eyes and instinctively Sherburne seemed to realize that with all his care in using typewriters and telephones, some kind of record of his extortion had been obtained.

For a moment he crumpled up. Then Kennedy seized him by the elbow, dragging him toward a side door opposite that at which our cab was standing.

"I mean," he muttered, "that I have the goods on you at last and you'll get the limit for blackmail through this little wax cylinder if you so much as show your face in New York again. I don't care where you go, but it must be by the first train. Understand?"

A moment later we returned to the cab, where it had pulled up in the shadow, away from the carriage entrance.

"You--you'll forgive me--for my--unjust suspicions--Agatha?" we heard a voice from the depths of the cab say.

Kennedy pulled me back in time not to interrupt a m.u.f.fled "Yes."

Craig coughed.

As he reached a hand in through the cab door to bid good-night to the reunited couple, I saw Mrs. Seabury start, then turn and drop into her handbag the key which Kennedy had extracted from Sherburne's pocket in the _melee_ and now conveyed back to her in the handshake.

CHAPTER VII

THE DIAMOND QUEEN

"Meet _Sylvania_ Quarantine midnight. Strange death Rawaruska. Retain you in interest steamship company. Thompson, Purser."

Kennedy had torn open the envelope of a wireless message that had come from somewhere out in the Atlantic and had just been delivered to him at dinner one evening. He read it quickly and tossed it over to me.

"Rawaruska," I repeated. "Do you suppose that means the clever little Russian dancer who was in the 'Revue' last year?"

"There could hardly be two of that unusual name who would be referred to so familiarly," returned Craig. "Curious that we've had nothing in the wireless news about it."

"Perhaps it has been delayed," I suggested. "Let me ring up the _Star_.

They may have something now."

A few minutes later I rejoined Craig at the table. A report had just been received that Rawaruska had been discovered, late the night before, unconscious in her room on the _Sylvania_. The ship's surgeon had been summoned, but before he was able to do anything for her she died. That was all the report said. It was meager, but it served to excite our interest.