Bumper was so young and inexperienced that he didn't know a drain-pipe from an ordinary hole in the ground, nor for that matter a tree trunk that was hollow inside from a rabbit's burrow. Bumper was a city-bred rabbit, born in the backyard of a tenement house, and how could you expect him to know much of the things that ordinary wild rabbits learn by heart before their whiskers begin to sprout?

When he opened his eyes the next morning, he stretched himself, and blinked hard at the circular roof over his head, wondering what sort of a house he was in now. It took some time for his brain to recall the events of the previous night. Then he sat up and smiled.

"Ho! Ho!" he laughed. "Carlo must have had a long, cold wait outside for me. I think I'll take a peek at him."

He was really anxious to see if the little girl was up yet, and if she had missed him. He had perfect confidence in her, and knew that she would call off the dog the instant she saw him.

Bumper could see that it was morning, for the bright light shining through the big end of the drain-pipe proved that. He crawled along cautiously, making as little noise as possible. If Carlo was waiting at the entrance to pounce upon him, he wasn't going to be caught napping.

Another thing which drew him toward the mouth of the pipe was the fragrant odor of good things from the garden. In spite of the big feast of the night before, Bumper was hungry again, and he longed to get back in the garden and devour a few more carrots and crisp lettuce leaves.

He was within a few feet of the mouth of the drain-pipe, quite confident that Carlo had grown tired of watching and left, when a shadow came between him and the light. Bumper caught sight of a head and forelegs thrust 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 unnecessary. He disliked Mr. Sewer Rat and all his tribe, for they had often made their way into the old woman's backyard to annoy the young bunnies. Besides his bad manners and uncouth ways, the Sewer Rat was disgustingly dirty in his habits. How could he be otherwise when he chose to live in sewers rather than in clean quarters above ground?

"Why were you running so fast?" asked Bumper, not willing to admit the rat had frightened him.

"Just to frighten you," was the retort. "I wanted to give you the scare of your life, and I guess I did."

"Oh, no," replied Bumper, assuming an air of dignity. "I wasn't really frightened so long as I knew you were behind me. Carlo couldn't catch me until he nabbed you."

"Carlo! Who's Carlo!" demanded the Sewer Rat, pretending ignorance.

"Oh! Ho!" laughed Bumper. "Don't pretend that Carlo, the dog, wasn't after you. Didn't I see him chase you in the hole? And how frightened you looked! Why, it nearly made me die with laughter."

Mr. Sewer Rat puffed up his cheeks and gnashed his long, white teeth angrily. Bumper's fling had hit the mark.

"If Carlo ever touches me," he said, "I'll bite his nose so he'll remember it. Who's afraid of an old dog like Carlo?"

"You are, I should say," smiled the white rabbit.

The Sewer Rat started to deny this, and then thought better of it. "Well, I wasn't more frightened than you, Mr. White Rabbit. You're as pale as a ghost this very minute."

"That's a good one," laughed Bumper. "Pale as a ghost! Why, I'm whiter than snow all the time. How could I get paler?"

Mr. Sewer Rat gnashed his teeth again, and swished his long tail. He was plainly angry and discomfitted. So he retorted maliciously:

"You're not white at all. You're so dirty your own mother wouldn't know you. White! Oh! Ho! Ho! I wish you could see yourself."

Bumper did see himself, or, at least, a part of himself. Both front paws were muddy; his long ears were covered with iron rust; his fat cheeks were dusty and cobwebby, and to the ends of his whiskers clung specks of dirt. In his progress through the drain-pipe he had accumulated sufficient dirt to change his color from pure white to a rusty gray.

"I can soon clean myself," he remarked, "and the little girl with the red hair will help me. Is that the hole that leads back to the garden?"

The Sewer Rat suddenly blinked his wicked little eyes. "Yes," he replied, "if you know the right turns to take. If you don't you'll get lost, and never find your way out."

"I think I know my way back," said Bumper, hesitatingly. He hated to ask favors of the Sewer Rat, but when the latter volunteered information he was grateful for it.

"You'll find a better way back to the garden by following the abandoned sewer you're standing in. Keep straight on to the end. It's much better than crawling back through this small drain-pipe."

"Thank you!" replied Bumper. "I believe I'll go back that way!"

"All right, then. I must be going to my family. I haven't had my breakfast yet. Good morning!"

Bumper thanked him again, and turned to follow the sewer back to the garden, not realizing that the Rat had purposely deceived him out of revenge.