won the race when Janet, glancing
back toward the toboggan slide, gave a cry of alarm.

"Look at Trouble!" she exclaimed.

There, on top of the pile of big boxes, having climbed to the platform
by means of the rickety steps, stood baby William.

"I s'ide down!" he cried, jumping up and down in delight. "I s'ide!"

"No! No! Don't! Stand still, Trouble! Don't move! I'll come and get
you!" shouted Ted.

He started on a run, but he was too late. A moment afterward Trouble was
in trouble, for the little fellow toddled toward the back edge of the
platform, which had no railing to guard it, and a second later he seemed
to topple off backward.

CHAPTER II

THE POSTMAN'S WHISTLE

"Oh, Trouble has fallen! Trouble has fallen!" screamed Jan, as she ran
around toward the back of the toboggan.

"Come on, Tom!" yelled Ted. "I guess my little brother's hurt!"

Lola followed the others, and as the four children raced to the aid of
baby William a shrill whistle was heard near the front of the house.

"Is that a policeman?" cried Tom to his chum.

"No, it's the postman," answered Ted. "He's taking a letter into our
house. Hey, Mr. Brennan!" he called, as he saw the gray-uniformed mail
carrier entering the yard. "My little brother's hurt!"

Screams coming from the mouth of William seemed to tell that he was
badly frightened, anyhow, and also hurt, very likely.

"Trouble hurt? I'm coming!" cried the postman dropping his bag of mail
and running around the side path.

Another moment and the Curlytops and their playmates had reached the
rear of the high pile of boxes from which the toboggan slide started.
They looked on the ground, expecting to see Trouble huddled there in a
crumpled heap.

But he wasn't there. His voice, however, could be heard crying lustily,
and it seemed to come from overhead. Yet the little boy was not on the
high platform, from which he had been seen to topple backward.

Where was Trouble?

This was the question the Curlytops asked themselves. And it was what
their playmates wanted to know, as did the postman.

But before we settle that question I want to answer several inquiries
that I feel sure some of my new readers are asking, and among these is
this:

"Who are the Curlytops?"

Those who have read the previous books of this series do not need to go
over this part I am writing now. They may skip it and get on with the
story. Others may wish to know something about Ted, Janet and Trou