e convict decided that there was nothing for it except
to let Mr. Wagg do the wagging.

When the noon bell clanged from the tower, the pit-job prisoners
filtered into groups from their occupation in the yard and others filed
from the doors of the shops. They shuffled their way in double lines
through the gaping door of the main building, received their tins of
food, and went to their cells.

As usual, Vaniman remained with Wagg.

The warders on the walls relaxed their vigilance when the heavy door was
closed behind the last men of the lines. The guards went into the sentry
boxes and set down the heavy rifles.

Wagg made a general survey of the scene. No person was moving in the
open area of the yard. The veteran of the guard was well acquainted with
the customary habits and movements of the noon hour. He knew that the
men in the main guardroom were reduced to a shift of two while the
others went to their dinners; the two men were in the habit of giving
the deserted yard only indifferent attention. But Mr. Wagg had provided
against even casual glances.

For purposes of his own, which a boss did not need to explain, he had
nailed boards together to form something like a door, six feet square.
The thing had been leaning against the dynamite shed for some days.

Quite casually, Mr. Wagg went and lifted away this square of boarding,
holding to the traverse braces on which the boards were nailed. He
trudged along, carrying it, and came to where Vaniman was standing,
observing and wondering.

"Scooch!" snapped Wagg. "Walk along. Don't show yourself past this
shield!"

It was a true shield. Wagg carried it straight up and down. Vaniman
obeyed instantly. He had a mental flash that Wagg did know exactly what
he was about in his tactics. Lacking all idea of the scheme, Vaniman
had not the heart to begin to ask for any details of the big plan at the
crucial moment. He allowed himself to be an automaton. It was easy to do
one thing at a time, as Wagg commanded; knowing nothing about what Wagg
intended to do. Vaniman was not in a position to delay matters by
doubts as to the best way of doing the thing. He walked behind the board
screen, conscious that his movements were hidden from the men in the
guardroom and, for that matter, from the eyes of anybody in the prison
building.

After a walk of a few rods Vaniman found himself close to a big chimney;
it served a shop which had been unused since the crew had been at work
on