“Over the lake!” cried Mrs. Bobbsey.  “Oh, if they should fall in!”

“The balloon will float on the water,” her husband told her.  “The children will be all right, I’m sure.”

“Yes, indeed,” agreed Mr. Trench.  “Don’t worry, lady.  We’ll get your children back.  The first thing to do is to go to the lake, and then we can hire a motor-boat there.”

“I’m going with you!” declared Mrs. Bobbsey, as she saw the preparations being made for the searching party.

“I think you had better stay with Bert and Nan,” said Mr. Bobbsey.

“Oh, we’ll be all right!” Nan hastened to tell her father.

“Can’t Harry and I come on the searching party?” asked Bert.

“No, I would rather not,” his father answered.  “You stay with your mother and Nan.”

“I simply am coming with you, Dick!” said Mrs. Bobbsey, and when she spoke in that tone her husband knew there was no use trying to get her to change her mind.

“Very well,” agreed Mr. Bobbsey.  “We will go to the lake in my auto.  Mr. Trench knows where we can hire a motor-boat.”

The lake, a large one, came within a few miles of the fair grounds.  The balloon man knew in which direction the water lay, and he had seen the wind carrying the big gas bag toward the water.

“Bert, you and Nan and Harry must go back to Meadow Brook Farm,” directed Mr. Bobbsey.  “I’ll see if I can’t hire an auto to take you there, as it is going to storm soon.  It’s sprinkling now.”

“We’ll take them back,” offered a gentleman who had come to the fair with his wife in their auto.  “I know where Meadow Brook Farm is.  We’ll take these children there.”

“Thank you, very much,” said Mr. Bobbsey.  “And tell your uncle and aunt what has happened, Bert.  Tell them we expect to be home before night with Flossie and Freddie.”

“Oh, if we only can be!” exclaimed Mrs. Bobbsey.

“We’ll find the little ones all right—­never fear!” said Mr. Trench.  “If you’re ready now, we’ll start.”

So while Nan, Bert and Harry remained behind in charge of Mr. Blackford, who had offered to take them home in his automobile, Mr. and Mrs. Bobbsey, with some men who had charge of the balloon, started off to go to the lake, there to hire a boat and search for Flossie and Freddie.

“They’re out of sight.  How far away they must be!” sighed Mrs. Bobbsey, as she entered the automobile.  She looked up, but could not see the balloon, so fast had it been blown away.

“They aren’t so far as it seems,” declared Mr. Trench.  “It’s getting foggy, and it’s going to rain hard soon.”

As Bert, Nan, and Harry were getting in Mr. Blackford’s automobile to go to Meadow Brook Farm, Bob Guess came hurrying up through the rain.  The merry-go-round, as well as other amusements at the fair, had shut down on account of the storm.

“Where’s your father?” asked Bob of Bert.  “I’ve something to tell him.  Where is he?”