passed by. He went on to
repeat the evidence dragged from him at the inquest as the result of the
eavesdropping of Mr. Lazarus Lowch, telling over again of the weird
scream that had startled them a few minutes after the passing of the
second unseen pedestrian. And he finished his narrative with the hurried
return along the path of a man who, as he passed their lair, was shown
by the searchlight on the battleship to be none other than Leslie
Chermside.

Mr. Mallory pondered the statement, then asked suddenly, "Did you notice
any peculiarity in the footfall of the invisible pedestrians?"

"Yes, we did," Enid answered quickly. "The first to come along was going
rapidly, as though he was late for an appointment--almost running, in
fact. We could quite plainly hear him puffing and blowing."

"Humph! Cannot you be a little more exact as to the time that elapsed
between these four different incidents--the passing of the two unseen
wayfarers, the scream, and the disclosure of Chermside by the
searchlight? For instance, could the second of the two invisible
passers-by have reached the spot where the body was found, when you
heard the scream?"

"I couldn't say, sir," replied Reggie with a faint grin at his companion
of the fatal night.

"Or whether, after the scream, there had been sufficient time for
Chermside to traverse the distance from the same spot to where you
were?"

"You see, father," Enid took up her parable as Reggie shook his head,
"we didn't know then of any reason for paying attention to these
matters. We were discussing things that seemed of far greater
importance," she added demurely.

The old diplomatist was in too serious mood to give rein to his sense of
humour just then. He allowed his daughter's naive confession to pass
unheeded, and, walking to the window, tried, as men do when face to face
with a knotty problem, to concentrate his thoughts by fixing his gaze on
some immaterial object. The study window was at the side of the house,
with a distant view of the red point at the mouth of the river, and his
eyes unconsciously sought that soothing picture without causing any
reflex action on the clever brain busy with affairs of more human
interest. Close under the window ran the path leading from the
tradesmen's entrance to the back door.

"Your vagueness as to time makes it uncertain," Mr. Mallory said
presently, "whether Chermside was one of the two men who passed you in
the first instance, going out