Bets went to join the others, very pleased with herself. Her blue balloon floated behind her, tugging at its string.

"Here she is at last!" said Pip. "We thought you were never coming, Bets. What's up with you? You look bursting with something."

"Do I?" said Bets. "Fancy that! By the way, I've a message from Fatty. We're to go home at six and he will meet us somewhere."

"Who gave you that message?" said Pip, at once.

"That's my secret," said Bets annoyingly.

"Did you speak to Fatty himself?" demanded Larry. "Is he the Hoopla-man?"

"I shan't tell you," said Bets. "I'm going to keep my secret for a bit!"

And she wouldn't say another word, which annoyed the others very much. Fancy young Bets knowing something they didn't know!

At six o'clock they made their way back through the Fair, across the level-crossing, and up the lane from the river. Sitting on a bench, with her balloons, was the old Balloon-woman, waiting for them. She got up as they came.

"Balloons!" said she. "Strong balloons!"

"No thanks," said Pip, and walked on. The old woman walked with him. "Buy a balloon!" she said, "Just to help me, young sir!"

"No thanks," said Pip again, and walked a little faster. But the old dame could walk surprisingly fast too. She kept up quite easily with Pip!

"Do buy a balloon!” she said, her voice cracking queerly.

How long she would have pestered Pip nobody knew—but Bets suddenly exploded into a series of helpless giggles that took the others by surprise. They stared at her.

"What is the matter?" said Pip, exasperated.

"Oh dear!" gasped Bets. "Oh dear—I'm sorry. But I can't help it. It's all so f-M-funny!"

"What's funny?" shouted Pip. And then he stared—for the old Balloon-woman, pulling her skirts above her knees, and showing sand-shoes and bare legs, was doing a lively jig in front of him and round him, making peculiar noises all the time.

"Don't, Fatty, don't! I shall die of laughter!" said Bets, holding her aching sides.

The others stared as if their eyes were about to fall out. "What—it's Fatty!" said Pip. "Fatty! It isn't. I can't believe it!”

But it was, of course. As soon as Fatty "unscrewed" his face, as Bets called it, and got rid of his lines and wrinkles, every one could see quite well it was Fatty.

Larry and Daisy were speechless. So Fatty hadn't been the Hoopla-man, or the Roundabout-man either. He was the old Balloon-woman instead. Trust Fatty to think out a disguise that nobody would guess!

Or had little Bets guessed it? The others looked at her smiling face. Larry dragged the Balloon-woman to a wayside seat, and they all sat down.

"Is it really you, Fatty?" said Larry. The old woman nodded.

"Of course! Golly, this disguise must be super if I could take you all in as well as that!”

"Did Bets guess? " demanded Pip.

"She did," said Fatty. "She suddenly guessed when she was buying her balloon, and you had all gone off without her."

"But how did she guess?" said Pip, annoyed.

"Goodness knows!” said Fatty. "How did you guess, young Bets?"

"Oh, Fatty—it was such a silly thing—I don't really like to tell you," said Bets. "I'm sure you'll think it was a silly way to guess."

"Go on—tell me," said Fatty, with much interest.

"Well, Fatty—you see, you had very dirty hands, like all the rest of the Fair people," said Bets. "But I couldn't help seeing that you had nice, clean nails—and it did seem to me a bit funny that somebody with dirty hands should bother to keep their nails so clean."

"Well, I'm blessed!" said Fatty, looking down at his dirty hands, and examining the well-kept nails. "Who would have thought of any one noticing that? Very very careless of me not to get some dirt into my nails when I made my hands filthy. I never thought of it. Bets, you are very clever. Most intelligent."

"Oh, Fatty—not really," said Bets, glowing all over her face at such generous praise.

"Well, I must say I think it was jolly cute of young Bets to notice a thing like that," said Larry. "I really do. We all had a chance of noticing, because we all stood in front of you. But it was Bets who spotted it. Jolly good, Bets!"

"She wins my second-best propelling-pencil," said Fatty. "I'll give it to you when I get home, Bets. In fact I'm not sure that I oughtn't to give you my best one. That was a really smart bit of work. Bright enough for a first-class detective!”

Daisy praised Bets too, but Pip was rather sulky. He was afraid his little sister would get swollen-headed. "If you say much more, Bets will want to be head of the Find-Outers," he said.

"Oh no, I shan't," said Bets happily. "I know it was only a bit of luck, really, Pip. You see, I actually put the pennies into Fatty's hands, and that's how I noticed the clean nails. Pip, I’ll lend you the propelling-pencil whenever you want it. See?"

That was so like Bets. Not even a cross elder brother like Pip could sulk for long with Bets. He grinned at her.

"Thanks, Bets. You're a good Find-Outer, and a good little sport too!"

"I say—look out—here's Goon!” suddenly said Larry, in a low voice. "Better pretend we're not with Fatty, or Goon will wonder why we are hobnobbing with an old Fair woman!"

So they all got up, and left Fatty behind on the seat, with his string of balloons bobbing over his head. Mr. Goon was on his bicycle as usual. He pretended not to notice the children at all. He always seemed busy and important these days!

But he got off his bicycle when he saw the old woman. Fatty was drooping over, pretending to be asleep.

"Here, you!" said Goon. "Move on! And where's your licence to sell balloons?"

The others heard this, and looked alarmed. Did you have to have a licence to peddle balloons? They were sure Fatty hadn't got one.

Fatty took no notice, but gave a gentle snore. Mr. Goon shook the shoulder of the Balloon-woman, and Fatty pretended to awake with a jerk.

"Where's your licence?" said Goon. He was always rude and arrogant to people like the old Balloon-woman.

"What did you say, sir?" said Fatty, in a whining voice. "Want to buy a balloon, sir? What colour do you fancy?"

"I don't want a balloon," said Goon angrily. "I want to see your licence."

"Oh, ah, my licence?" said Fatty, and began to pat all over his extremely voluminous skirts, as if to find where a licence would possibly be hidden. "Somewhere about, sir, somewhere about. If you can just wait a few minutes, kind sir, I'll find it in the pocket of one of my petticoats. An old woman like me, sir, she wants plenty of petticoats. Sleeping out under hedges is cold, sir, even on a summer night."

"Gah!" said Goon rudely, mounted his bicycle and rode off, ringing his bell furiously at a small dog that dared to run across the road in front of him. Was he, the Great Goon, in charge of a First-Class Case, going to wait whilst an old pedlar-woman fished for ages in her petticoats for a licence he didn't really want to see? Gah!

When Goon was safely out of sight the others went back to Fatty, amused and half-alarmed. "Oh, Fatty! How can you act like that with Goon? If only he'd known it was really you!"

"I enjoyed that," said Fatty. "Good thing Goon didn't wait to see my licence though, because I haven't got one, of course. Come on—let's get back home. I'm dying to take off these hot clothes! I’ve got layers of petticoats on to make me fat and shapeless!”

On the way up the village street they passed the bench where they had spoken to the old man on their way to the Fair that afternoon. Bets pointed him out to Fatty.

"Fatty. Do you see that old fellow, sleeping on that bench over there? Well, we thought he was you! And we went and called him Fatty, and Pip gave him a poke in the ribs!”

Fatty stood and looked at the old chap. "You know, it would be quite easy to disguise myself like him," he said. "I've a good mind to try it. Honestly, I believe I could."

"But you couldn't make your ears like his," said Bets. "He's got awful ears."

"No, I couldn't. But I could pull my cap down lower man he does, and hide my ears a bit," said Fatty. "Yes, that would be a very good and easy disguise indeed. I'll try it one day. Did Pip really .poke him in the ribs?"

"Yes. And the old fellow kept on saying, 'Wassat? Wassat?'" said Pip, with a giggle. "He's deaf, poor old thing."

The old man suddenly opened his eyes and saw the children looking at him. He thought they must have spoken to him. He cupped one of his ears in his hand and croaked out his favourite word, "Wassat?"

The old Balloon-woman winked at the children and sat down beside the old fellow. "Fine evening," she said, in the cracked voice the children were beginning to know well.

"Wassat?" said the old man. Then be sniffed, and wiped his nose deftly with the back of his hand. Fatty did exactly the same, which made Bets giggle in delight.

"FINE EVENING," said Fatty. "AND A FINE MORNING TOO!"

"Don't know nothing about mornings," said the old man surprisingly. "Always sleep till midday, I do. Then I gets up, has my bit of dinner, and comes out into the sun. Mornings don't mean nothing to me."

He sniffed again, and then took out his pipe to fill it. Fatty watched all he did. Yes, it would be a marvellous thing to do, to disguise himself as this old fellow. Pipe, sniffs, deafness, and all—Fatty could do it!"

"Come on, Fatty!" said Pip, in a low voice. "We really will have to get back. It's getting late."

Fatty got up and joined them. They soon parted and went their different way—Pip and Bets down their lane, and Larry and Daisy up theirs. Fatty went in at his back gate, and his mother caught sight of the old Balloon-woman, as she stood in the garden, cutting sweet-peas for the table.

"A friend of Cook's, I suppose," she thought; "or is she trying to sell balloons here?"

She waited for the Balloon-woman to come back again, but she didn't. So, rather curious, Mrs. Trotteville went to the kitchen door and looked in. There was no Balloon-woman to be seen—only Cook, red in the face, cooking the dinner.

"Where did that old Balloon-woman go?" said Mrs. Trotteville, in wonder. But Cook didn't know. She hadn't seen any old woman at all. And no wonder—for at that moment the old Balloon-woman was stripping off layers of petticoats down in the shed at the bottom of the garden—to come forth as a very hot and rather untidy Fatty.

"What a peculiar thing for a Balloon-woman to vanish into thin air!" thought Mrs. Trotteville. And so it was.