Pip and Bets sat in their garden, in the very coolest place they could find, They had on sun-suits and nothing else, for the August sun was blazing hot.

"A whole month of the summer hols gone already!" said Pip. "And except that we've been away to the seaside for two weeks, absolutely nothing else has happened. Most boring."

"The boringest hols we've ever had," said Bets. "Not even the smell of a mystery to solve I And not even Larry, Daisy, Fatty, or Buster to play with—they've been away at the sea for ages!"

Larry and Daisy were friends of Pip and Bets, and so was Frederick—or Fatty as everyone called him. Buster was his Scottie dog, loved by all the children.

The five children called themselves the Five Find-Outers and Dog, because for the last four holidays they had tackled curious mysteries and solved them all—much to the annoyance of the village policeman, Mr. Goon.

"But now it seems as if you and I, Pip, are the only Find-Outers left," said Bets. "I don't feel as if the others will ever come back! Soon the hols will be over, you'll all be back at boarding-school again, except me, and we shan't solve any mystery at all these hols."

"There are still four weeks left, so cheer up, baby!" said Pip. "And the others come back this week—and I bet old Fatty will have heaps of new disguises to try out on us! We'll be on the look-out for him this time, though—and we jolly well won't be taken in!"

Bets laughed. She remembered how Fatty had disguised himself as a French boy, and deceived them all beautifully. And in the last holidays he had produced all kinds of disguises, which he wore with a red wig and eyebrows. There was no knowing what old Fatty would be up to next!

"But this time he won't deceive us," said Pip again. "I shall be very suspicious of any peculiar-looking stranger who tries to talk to me, or comes to call on us. I shall say to myself, 'It's you all right, Fatty,' and I shan't listen to a word!"

"Do you think there will be a mystery for us to solve these hols?" asked Bets. "I do so like looking for clues, and making out lists of Suspects, and crossing people off the list when we've made enquiries—and finding the real Suspect at the end!"

"We've been jolly lucky so far," said Pip, sitting up and looking round for the bottle of lemonade he had brought out. "We've been able to solve every single mystery. We can't always be successful, though. I don't expect even real detectives are always successful. Bets, you pig, you've finished the lemonade. Go and ask Gladys for some iced water."

Bets was too lazy to move. She rolled over out of Pip's reach, and yawned loudly. "I'm bored! I want the others to come back so that we can have games with them. I want a mystery—a really good one. And I want to solve it before Old Clear-Orf does!"

Old Clear-Orf was Mr. Goon the policeman. He told children and dogs to "clear-orf" whenever he saw them. He disliked all the Find-Outers intensely, and never had a good word to say for them. Pip and Bets hadn't seen much of him in the summer holidays, and were very glad, for he had often been to their parents to complain of the behaviour of the Five Find-Outers. Bets was afraid of him, because when he lost his temper he shouted, and was very unpleasant indeed.

"Bets, didn't you hear me tell you to go in and fetch some iced water?" said Pip crossly. "Go on!"

"I'm not going to be ordered about by you," said Bets, rolling a bit farther away. "I suppose you order all the little boys about in your school, and then when you come home you think you can order me about too. Well, I shall soon be ten, and you're not to!"

"Don't you cheek me, young Bets!" said Pip, sitting up. "You're much younger than I am, and you've got to do as you're told! Go and get that iced water—or I’ll catch you and give you a jolly good smacking."

"I think you're a horrid brother to have," said Bets. "I'd much rather have Fatty. He's always kind to me!"

"He wouldn't be, if you were his sister," said Pip. "He hasn't got any sisters—if he had, he'd know what a nuisance they are. Now—are you going to go and ..."

"Yes, I’ll get it!" said Bets, getting up, "but only because I'm thirsty, and I want some to drink, see? I don't mind bringing you out a little too, as I'm going to get some for myself, but I'm really going for myself, and..."

Pip pretended to be getting up, and Bets fled. If only the others would come back! She and Pip were getting tired of one another.

Bets hadn't long to wait before the others came back. In two days' time Larry, Daisy, Fatty, and Buster all turned up together, looking so brown that Pip and Bets had to gaze earnestly at them to make sure they really were their friends. Buster wasn't brown, of course—he was still jet-black, and he flung himself on Pip and Bets in joy and delight, barking and licking and whining as if he had gone mad.

"Buster, darling! You're fatter! Oh, Larry, I'm glad you're back! Daisy, you're terribly brown. And oh, Fatty—you've grown!"

Fatty certainly had grown in the last four months. He was still plump, but he was taller, taller even than Larry now, and much taller than Pip, who didn't seem to have grown at all in the last year.

"Hallo, every one!" he said, and Bets gave a cry of surprise.

"Fatty! You've got a different voice! It's a grown-up voice! Are you putting it on—disguising it, I mean?"

"No," said Fatty, pulling Bets' hair teasingly. "It's just broken, that's all."

"Who broke it?" said Bets, in alarm, and the others roared at her till their sides ached.

"She'll never be anything but a baby!" said Pip. "Never."

Bets looked so upset and puzzled that Fatty put his arm round her and gave her a squeeze. "Bets, don't be silly. You know that when they grow up, boys get deep voices like men's, don't you? Well, when boys' voices change Eke that we say that their voices break—that's an. We don't mean broken in half, or smashed to pieces!"

"Oh, Fatty—I don't know you with such a deep voice," said Bets, half-alarmed. "You don't sound the same. You look like Fatty—but you don't sound like him! I wish you had your old voice."

"Bets, you've no idea what a difference it makes to me, now I've got a proper grown-up voice," said Fatty earnestly. "It means that I can disguise myself as a grown-up instead of always like some kind of boy! It gives me much more scope—and I've got some fine grown-up disguises!"

Bets immediately changed her mind about not liking Fatty's new voice. More disguises I Now life would be exciting and thrilling and unexpected things would happen. Fatty would disguise himself as all kinds of grown-up people—the Find-Outers would have a simply gorgeous time. She stared at Fatty happily.

"Oh, Fatty! You've only been able to dress up as telegraph boys or butcher boys or messenger boys before! Now you can be all kinds of things—old men with beards—a postman—a dustman—a window-cleaner with a ladder—even a sweep! Oh, Fatty, do be all those things and let's see you!”

Every one laughed. "Give me a chance!" said Fatty. "I'm going to practise a bit these hols. I didn't have much chance whilst I was away, because Mother wouldn't let me take much luggage—but I don't mind telling you I'm going to collect a few things now! I've got taller too, so I can almost wear grown-ups' things. By the time our next mystery comes along I shall be able to tackle it in whatever disguise is necessary."

"You do sound grown-up," said Bets. "Doesn't he, everybody?"

"Well, as a matter of fact," said Fatty, swelling up a little with pride, "I'm the tallest boy in my form now, and you should just see the muscles in my arms. I'll show you!”

"Same old Fatty!" said Larry. "Best in everything, aren't you? Nobody to beat you!"

Fatty grinned and peeled off his shirt. He bent his arm and showed them how his muscles came up in a big lump. Bets looked on in awe, but Larry and Pip did not seem to be much impressed.

"Fair!" said Larry. "I've seen better ones on a boy of twelve!”

"Huh! You're jealous!" said Fatty, good-humouredly. "Now then—let's hear any Peterswood news, Pip and Bets. The village seemed pretty crowded when I came through it just now."

"Too jolly crowded for anything!" said Pip. "This hot weather is drawing the people to the river in their hundreds! We get motor-coaches all day long—and down by the river there are all sorts of shows to amuse the people when they get tired of the river, or it's raining."

"What sort of shows?" asked Fatty, lying down on the grass, and tickling Buster on his tummy. "Any good?"

"Not much," said Pip. "There's a Waxwork Show—pretty dull really—you know, figures made of wax, all dressed up—and there are those Bumping Motor-Cars—they're quite fun for the first two or three times you go in them...."

"And a Hoopla game," said Bets. "You buy three wooden rings for twopence, and you try to throw them over any of the things arranged on a big round table—and if the ring goes right over anything, you can have whatever you've ringed. I like that game."

"You would!" said Pip. "She spends a whole shilling on hiring the wooden rings—and then wins a mouldy little brooch worth a penny, that Mother can't bear and won't let her wear!”

"Well, Pip, you spent tenpence once, and you didn't win a thing!" began Bets hotly. But Fatty interrupted.

"Sounds as if Peterswood is going quite gay!" he said. "Well have to make up a party and go down to all these shows one wet afternoon. If it ever is wet again!"

"Fatty, win you go in one of your new grown-up disguises?" asked Bets excitedly. "Oh, do! It would be lovely to see you acting like a grown-up, and taking everybody in!"

"Ill see," said Fatty. "I'd like to take in Old Clear-Orf, I must say! He's up to all my boy-disguises now—he'd see through them at once—but I bet he wouldn't see through a grown-up disguise!"

"What will you go as?" asked Daisy.

"Don't know," said Fatty. "And listen, all of you—if you can get any old things of your fathers'—you know, old hats they don't want, or boots, or even old coats—they'd come in mighty useful for me. I'm afraid if I take too many of my father's things, he'll be annoyed. Mother doesn't let him keep any of his old things, she gives them away—so he's only got rather newish clothes."

"We'll do what we can," promised Larry, and Pip nodded too. Anything to help old Fatty to disguise himself! Bets sighed with joy to think that Fatty was back again. Now life would really be exciting once more. And oh, if only a mystery turned up, how heavenly the rest of the hols would be!