nging under the left arm at his side. Kirby had brought no
revolver with him to Denver. Occasionally he carried one on the range
to frighten coyotes and to kill rattlers. But he knew where he could
borrow one, and he proceeded to do so.

Not that there was any danger in meeting the unknown correspondent.
Kirby did not admit that for a moment. There are people so constituted
that they revel in the mysterious. They wrap their most common actions
in hints of reserve and weighty silence. Perhaps this man was one of
them. There was no danger whatever. Nobody had any reason to wish him
serious ill. Yet Kirby took a .45 with him when he set out for the
Denmark Building. He did it because that strange sixth sense of his
had warned him to do so.

During the day he had examined the setting for the night's adventure.
He had been to the Denmark Building and scanned it inside and out. He
had gone up to the fourth floor and looked at the exterior of Room 419.
The office door had printed on it this design:

THE GOLD HILL MILLING & MINING COMPANY

But when Kirby tried the door he found it locked.

The Denmark Building is a little out of the heart of the Denver
business district. It was built far uptown at a time when real estate
was booming. Adjoining it is the Rockford Building. The two dominate
a neighborhood of squat two-story stores and rooming-houses. In dull
seasons the offices in the two big landmarks are not always filled with
tenants.

The elevators in the Denmark had ceased running hours since. Kirby
took the narrow stairs which wound round the elevator shaft. He trod
the iron treads very slowly, very softly. He had no wish to advertise
his presence. If there was to be any explosive surprise, he did not
want to be at the receiving end of it.

He reached the second story, crossed the landing, and began the next
flight. The place was dark as a midnight pit. At the third floor its
blackness was relieved slightly by a ray of light from a transom far
down the corridor.

Kirby waited to listen. He heard no faintest sound to break the
stillness. Again his foot found the lowest tread and he crept upward.
In the daytime he had laughed at the caution which had led him to
borrow a weapon from an acquaintance at the stockyards. But now every
sense shouted danger. He would not go back, but each forward step was
taken with infinite care.

And his care availed him nothing. A lifted foot struck an e