mised you--" What had he promised? What she received was death!
Had this been in his mind? Would this have been the termination of the
sentence had he wakened less soon to consciousness and caution?

Sweetwater dared to believe it. He was no nearer comprehending the
mystery it involved than he had been before, but he felt sure that he
had been given one true and positive glimpse into this harassed soul
which showed its deeply hidden secret to be both deadly and fearsome;
and happy to have won his way so far into the mystic labyrinth he had
sworn to pierce, he rested in happy unconsciousness till morning when--

Could it be? Was it he who was dreaming now, or was the event of the
night a mere farce of his own imagining? Mr. Brotherson was whistling
in his room, gaily and with ever increasing verve, and the tune which
filled the whole floor with music was the same grand finale from William
Tell which had seemed to work such magic in the night. As Sweetwater
caught the mellow but indifferent notes sounding from those lips of
brass, he dragged forth the music-box he held hidden in his coat pocket,
and flinging it on the floor stamped upon it.

"The man is too strong for me," he cried. "His heart is granite; he
meets my every move. What am I to do now?"

XIX. THE DANGER MOMENT

For a day Sweetwater acknowledged himself to be mentally crushed,
disillusioned and defeated. Then his spirits regained their poise. It
would take a heavy weight indeed to keep them down permanently.

His opinion was not changed in regard to his neighbour's secret guilt. A
demeanour of this sort suggested bravado rather than bravery to the ever
suspicious detective. But he saw, very plainly by this time, that he
would have to employ more subtle methods yet ere his hand would touch
the goal which so tantalisingly eluded him.

His work at the bench suffered that week; he made two mistakes. But by
Saturday night he had satisfied himself that he had reached the point
where he would be justified in making use of Miss Challoner's letters.
So he telephoned his wishes to New York, and awaited the promised
developments with an anxiety we can only understand by realising how
much greater were his chances of failure than of success. To ensure the
latter, every factor in his scheme must work to perfection. The medium
of communication (a young, untried girl) must do her part with all the
skill of artist and author combined. Would she disappoint them?