ied.

"This bottle contains a weak solution of the toxin of fatigue,"
persisted Kennedy.

I thought she would break down, but, by a mighty effort, she kept her
composure and said nothing.

"Someone was trying to discredit and ruin Murchie by making the horses
he trained lose races--somebody whose life and happiness Murchie himself
had already ruined.

"That person," pursued Kennedy relentlessly, "was defeated in the
attempt to discredit Murchie when, by my injection of the antitoxin,
Lady Lee finally did win. In that person's mind, Murchie, not the horse,
had won.

"The wild excitement over Murchie's vindication drove that person to
desperation. There was only one more road to revenge. It was to wait
until Murchie himself could be easily overpowered, when an overwhelming
dose of this fatigue toxin could be shot into him--the weapon that had
failed on the horses turned on himself. Besides, no one--not even the
most expert physician or chemist--would ever suspect that Murchie's
death was not natural."

"That--that bottle is mine--mine!" shouted a wild voice interrupting. "I
took it--I used it--I--"

"Just a moment, Miss Safford," entreated Kennedy. "That person," he
rapped out sharply, picking up the pedigrees O'Connor had handed him,
"that person gave the toxin to a poor dope fiend as a sleeping-potion in
one strength, gave it to Lady Lee in still another strength, and to
Murchie in its most fatal strength. It was the poor and unknown
pharmacist described in this pedigree whose dream of happiness Murchie
shattered when he captivated Cecilie Safford--her deserted lover, Ronald
Mawson."

CHAPTER XIX

THE X-RAY DETECTIVE

"I want to consult you, Professor Kennedy, about a most baffling case of
sudden death under suspicious circumstances. Blythe is my name--Dr.
Blythe."

Our visitor spoke deliberately, without the least perturbation of
manner, yet one could see that he was a physician who only as a last
resort would appeal to outside aid.

"What is the case, Doctor?" queried Craig.

The Doctor cleared his throat. "It is of a very pretty young art
student, Rhoda Fleming, who returned to New York from France shortly
after the outbreak of the war and opened a studio in the New Studio
Apartments on Park Avenue, not far from my office," began Dr. Blythe,
pausing as if to set down accurately every feature of the "case history"
of a patient.

"Yes," prompted Craig.

"About a week ago," the Doctor resu