rness. I
don't know what he may plot against us, but I'm certain he'll plot
something. Mr. Royce doesn't even know him by sight, and shouldn't be
worried; but, unless he's forewarned, he may walk right into danger. I
want you to help me keep an eye on him--to help me keep him out of
danger. If we look after him closely enough, I shan't need to warn
him. Will you help me?"

Her eyes were dancing as she looked up at me.

"Why, certainly!" she cried. "So we're to have a mystery--just we
two!"

"Just we two!" I assented with a quickened pulse.

She looked at me doubtfully for a moment.

"I must remember Mr. Graham's warning," she said. "You haven't
invented this astonishing story just to entertain me, Mr. Lester?"

"On my word, no," I responded, a little bitterly. "I only wish I had!"

"There," she said contritely; "I shouldn't have doubted! Forgive me,
Mr. Lester. Only it seemed so fantastic--so improbable----"

"It _is_ fantastic," I assented, "but, unfortunately, it is true. We
must keep an eye on Monsieur Martigny or Bethune."

"Which is his real name?"

"Those are the only ones I know, but I doubt if either is the true
one."

Royce and Mrs. Kemball joined us a moment later, and we sat watching
the low, distant Long Island shore until the gong summoned us to
lunch. A word to the steward had secured us one of the small tables in
an alcove at the side--Mrs. Kemball and her daughter surrendered the
grandeurs of the captain's table willingly, even gladly, to minister
to us--and the meal was a merry one, Mr. Royce seeming in such spirits
that I was more than ever determined not to disturb him with the
knowledge of Martigny's presence.

As the moments passed, my fears seemed more and more uncalled for. It
was quite possible, I told myself, that I had been making a bogy of my
own imaginings. The Frenchman did not appear in the saloon, and,
afterwards, an inquiry of the ship's doctor developed the fact that he
was seriously ill, and quite unable to leave his state room.

So afternoon and evening passed. There were others on board who
claimed their share of the charming Mrs. Kemball and her daughter. Mr.
Royce knew a few of them, too, and introduced me to them, but I found
their talk somehow flat and savorless. I fancied that my companion
looked slightly wearied, too, and at last we stole away to our deck
chairs, where we sat for an hour or more looking out across the
dancing waves, listening to the splash of th