“Would she really?” said Bets, wishing she could see Mrs. Trotteville in a blue fit. “Oh, Fatty - don’t get your money stolen, will you?”

“No detective would be such an idiot as that,” said Fatty scornfully. “Don’t you worry - the only person to take money out of my pocket is myself! Now, Buster, do be a good dog today. Come home tonight by yourself.”

“Woof!” said Buster politely. He always seemed to understand what was said to him.

“Have you left that invisibly written letter at Mr. Goon’s house yet?” asked Bets, with a giggle.

“No. I thought I’d send one of my friends down tomorrow with it,” said Fatty, grinning. “I didn’t want old Goon to see me. All right, all right, Mother. I’m just coming. I don’t mind if I do have to run all the way! Good-bye, Buster. Hold him, Bets, or he’ll tear after me all down the road to the station.”

Bets held Buster, who wriggled and struggled wildly, barking desperately. He couldn’t bear Fatty to go anywhere without him. Fatty disappeared after his mother, trotting down the drive like a fast pony.

“I hope Fatty will be able to get the things he wants,” said Pip. “It would be such fun to wear disguises.”

They went home with Buster, who at first looked very aggrieved and kept his tail down. But on being presented with a perfect giant of a bone by Bets he decided to get his wag back. After all, when Fatty went away he always came back again. It was just a question of waiting for him. Buster was prepared to wait, if he could while away the time with such a marvellous bone.

“It’s a pity old Fatty won’t be down for a day or two,” said Larry. “I hope his friends don’t stay long. He didn’t tell us who they were.”

“Some of his school friends, I expect,” said Pip. “Well, he’ll be down in two or three days’ time, and then we’ll have gorgeous fun looking at his disguises.”