mell the stuff. My turn will come again some
day."

But Brotherson did not drink. Setting down the glass he carried, he took
up the book lying near, weighed it in his hand and laid it down again,
with an air of thoughtful inquiry. Then he suddenly pushed it towards
Sweetwater. "Do you want it?" he asked.

Sweetwater was too taken aback to answer immediately. This was a move he
did not understand. Want it, he? What he wanted was to see it put back
in its place on the shelf. Did Brotherson suspect this? The supposition
was incredible; yet who could read a mind so mysterious?

Sweetwater, debating the subject, decided that the risk of adding to any
such possible suspicion was less to be dreaded than the continued threat
offered by that unoccupied space so near the hole which testified so
unmistakably of the means he had taken to spy upon this suspected man's
privacy. So, after a moment of awkward silence, not out of keeping with
the character he had assumed, he calmly refused the present as he had
the glass.

Unhappily he was not rewarded by seeing the despised volume restored to
its shelf. It still lay where its owner had pushed it, when, with some
awkwardly muttered thanks, the discomfited detective withdrew to his own
room.

XVIII. WHAT AM I TO DO NOW

Early morning saw Sweetwater peering into the depths of his closet. The
hole was hardly visible. This meant that the book he had pushed across
it from the other side had not been removed.

Greatly re-assured by the sight, he awaited his opportunity, and as soon
as a suitable one presented itself, prepared the hole for inspection by
breaking away its edges and begriming it well with plaster and old dirt.
This done, he left matters to arrange themselves; which they did, after
this manner.

Mr. Brotherson suddenly developed a great need of him, and it became a
common thing for him to spend the half and, sometimes, the whole of the
evening in the neighbouring room. This was just what he had worked for,
and his constant intercourse with the man whose secret he sought to
surprise should have borne fruit. But it did not. Nothing in the eager
but painstaking inventor showed a distracted mind or a heavily-burdened
soul. Indeed, he was so calm in all his ways, so precise and so
self-contained, that Sweetwater often wondered what had become of the
fiery agitator and eloquent propagandist of new and startling doctrines.

Then, he thought he understood the riddle. T