
Cardona, grim-faced and low-voiced, discussed the important problem with Inspector Klein. Although
he growled of a hidden murder, Cardona was forced to admit that the deaths might be the result of some
amazing accident. Until clews were gained, that must be accepted as the natural theory. Nevertheless,
both mystery and menace remained as great as ever.
While Cardona was discoursing thus, a powerful roadster coasted up to the parking lot, and a tall man
alighted. With a long, easy stride, this arrival walked toward the station platform. There he stood,
apparently waiting for a train.
Cardona became suddenly aware of the man's presence, and turned to stare at him. The man's eyes met
those of the detective. Cardona found himself gazing at a firm, calm face that was almost masklike in its
expression. From the sides of a sharp, hawkish nose, gleaming optics sparkled with strange, uncanny
gaze.
The appearance of the stranger was impressive. Cardona sensed a hypnotic power in those eyes.
Instinctively, the detective was sure that this man had overheard his remarks to Inspector Klein.
But the detective was loath to make a move. This man was here to take a train; he had come hours after
the death aboard the eight thirty-eight. Cardona could see no connection between this individual and the
case at hand.
Inspector Klein did not notice the man toward whom Cardona was looking. The inspector was watching
up the track; and now, at a moment when the stranger could hear, Klein made definite remarks without
turning his head in Cardona's direction.
"Stick here until three o'clock, Joe," ordered the inspector. "If you haven't landed anything by then,
there's no use wasting your time. You can leave a couple of men on duty; let them stay all night and
watch for the same train in the morning."
"I'll be here to-morrow morning," promised Cardona.
AN approaching train, coming around the bend, ended the conversation. Cardona, glancing toward the
hawk-faced stranger, noted that the man was watching the train intently.
The stranger stepped aboard, and that was the last Cardona saw of him. Yet, all during the remainder of
his fruitless investigation, Cardona could not help but recall the remarkable appearance of the man whom
he had seen upon the platform.
The detective had not noticed the stranger's arrival. He did not know that the powerful roadster belonged
to that man. When Cardona had hunches, he did not hesitate to follow them; but in this instance, Cardona
had no hunch. He was simply impressed by a chance observation; and he reasoned with himself that he
should forget this detail which had no apparent bearing on the death that struck at Felswood. Hence
Cardona did not inquire if any one had noted the stranger arrive.
It was shortly after three o'clock when Cardona reluctantly boarded a westbound train for Manhattan.
Extreme measures had brought no result. Grayson's body had been removed from the death car; and the
car itself was to be shunted from the siding.
Riding toward New York, Cardona mulled over the police surgeon's report, which corresponded exactly
with those on the two previous deaths. Grayson's system had shown traces of a poison. There must be
something odd and unexplainable about the unfound missile that had brought such immediate death.
As the train dipped into the tube beneath the East River, Cardona had a last thought of the stranger on