into the opening, and then, without stopping for further
investigation, he turned tail and ran back. There was a wild scampering
and scraping behind him, and he knew that Carlo was pursuing him in the
hole.

But Carlo couldn't follow him very far. The pipe narrowed so that there
was just room for Bumper to squeeze through, and no dog, certainly not a
big dog like Carlo, could catch him in there. When he reached the place
where he had spent the night, he stopped to look around him.

Horror of Horrors! Carlo or some other animal was close behind him,
blocking the entire entrance to the hole. Bumper could hear him scraping
along, and could almost feel his breath. A shiver of terror went clear
through him. In some strange manner the hole had been enlarged over night,
or Carlo had shrunk in size, or what seemed more probable, another dog
much smaller had taken up the pursuit.

With a little yip of fear, Bumper scrambled onward again, making his way
through the drain-pipe as fast as his feet would permit, which, after all,
was not so very fast, for he slipped and lost his footing a dozen times,
and once fell all in a heap where an elbow in the pipe brought him to an
abrupt stop. There were two holes opening before him, one leading to the
right and the other to the left.

Bumper chose the one to the right, and so did the animal pursuing him. The
race continued until the rabbit came to another branch where there seemed
to be three holes leading off into different directions. Bumper chose the
middle One blindly, and ran through it for dear life.

It was very dark, and it was impossible for him to tell where he was
going. His one great desire was to escape the pursuing dog or other animal
close behind him. Consequently, he was unprepared for the sudden climax of
his adventure.

The narrow tunnel came to an abrupt ending, and when Bumper shot out of it
he landed in a big, circular space that gave him plenty of opportunity to
turn around and look at his enemy. He had no more idea what kind of a
place he was in now than before. It was all so strange to him.

"Hello!" a voice called to him out of the small hole.

Bumper looked up, and saw a big Sewer Rat grinning at him from the mouth
of the drain-pipe.

"I never saw a rabbit run faster in all my days," laughed Mr. Sewer Rat.
"I couldn't keep up with you. What did you think was after you?"

Bumper was very angry and indignant now that he realized his flight was
all unneces