only state the facts. I do not pretend to explain them.

From the second hole the run passed into the masonry once more, zigzagged
upwards into the storeroom, and ended.

From the storeroom there were countless exists--down the gutter into
the courtyard (a short cut to the shambles), beneath the flooring to the
scullery, and thence along the drain-pipe to the great sewer, through the
ventilator on to the roof--anywhere, everywhere.

* * * * *

The scratching was certainly louder. The black rat was stepping very
delicately, but a slippery corn-husk shot from underneath his foot, and
with the rustle of the corn-husk the scratching ceased.

Nothing but a rat could have heard that; it was certainly a rat, but who?

For ten minutes he waited, listening. Then he stole forward, until the
points of his whiskers brushed lightly against the door. Instantly there
was a movement on the far side--a four-footed movement. Caution against
such cunning seemed superfluous. He boldly forced his nose between door
and flooring and sniffed; but only for a second, for his nose had gone
farther than he meant; the bottom of the woodwork had been gnawed through
until it was a bare half-inch thick all along its length. He drew back
with a jerk, and waited another ten minutes, staring at the door and
thinking.

The silence on the far side grew unendurable. The black rat whisked round,
and rushed madly for the run. He gained the shelf by a beautiful swinging
leap, easy and silent as a cat's.

[Illustration: HE STOLE FORWARD UNTIL THE POINTS OF HIS WHISKERS BRUSHED
LIGHTLY AGAINST THE DOOR.]

For the first few yards, between brickwork and wainscot, the run was
clear enough; but, as it turned upwards to the floor above, something
seemed unfamiliar.

The light, which had always faintly shimmered from the hole in the outer
wall, was gone. As he drove forward headlong, he bruised his nose against
the cause of its disappearance. The wall had been repaired with concrete.
It was utterly ungnawable, and he slowly retraced his steps to the cellar.
He was just in time to hear the scratching recommence.

[Illustration: HE TRIED TO STEADY HIMSELF BY NIBBLING AT A STRAY
CORN-EAR.]

It drew closer and closer. It got upon his nerves. He tried to steady
himself by nibbling at a stray corn-ear. He dropped it before he had
fairly tasted it, and crept forward to the door once more. There was more
than one unknown at work.