“I don’t know,” said Fatty. “No, probably not. Maybe just one or two of them.”

“Then they’re sure to take the letter to show the others, and bring them back here,” said the thin-lipped man. “We’ll keep a look-out for them. We’ll hide in the garden and catch the lot. Jarvis is downstairs now too. He can help.”

They opened some tins and had breakfast. They gave the hungry Fatty a small helping of ham sandwich, and he gobbled it up. They suddenly noticed his glass of yellow juice and one of them picked it up.

“What’s this?” he said, smelling it suspiciously. “Where did it come from?”

“It’s orange juice,” said Fatty, and he drank it up. “I had an orange with me and I squeezed it. I can’t help being thirsty, can I?”

He set down the glass. The men evidently thought no more of it but began to talk together in low voices, again using the language that Fatty did not understand. He was very bored. He wondered if one of the others would come soon. As soon as someone found he hadn’t got home, surely they would come and look for him! What were the Find-Outers doing?

They were all wondering how Fatty had got on that night. Bets was worried. She didn’t know why, but she really did feel anxious.

“I hope Fatty is all right,” she kept saying to Pip. “I do hope he is.”

“That’s about the twenty-third time you’ve said that!” said Pip crossly. “Of course he’s all right. Probably eating an enormous breakfast this very minute.”

Larry and Daisy called in at Pip’s soon after breakfast, looking cross.

“We’ve got to catch the bus and take some things to one of our aunts,” said Daisy. “Isn’t it a bore - just when we wanted to hear if Fatty found out anything. You and Bets will have to see if he’s home, Pip.”

“He may come wandering down, if he’s at home,” said Pip. “Oh, you’ve got Buster with you! Well, I’ll take him back to Fatty’s for you, shall I?”

Pip’s mother wouldn’t let him go out till about twelve o’clock, as she had made up her mind that he and Bets were to tidy out their cupboards. This was a job Pip hated. It took ages. Grumbling loudly, he began to throw everything out on to the floor.

“Oh, Pip, let’s hurry up and finish this job,” begged Bets. “I can’t wait to find out if Fatty’s home all right.”

Buster fussed round, sniffing at everything that came out of the cupboards. He was upset and worried. His beloved master hadn’t fetched him from Larry’s the night before, and here was the morning and nobody had taken him back to Fatty yet. Not only that, but they apparently wouldn’t let him go by himself! He was so miserable that he limped even more badly than usual, though his leg was now quite healed.

At last the cupboards were finished and Pip and Bets were told they might go out in the snow. They put on hats and coats, whistled to Buster, and set off to Fatty’s.

They slipped in at his garden door and whistled the tune they always used as a signal to one another. There was no reply.

A maid popped her head out into the passage. “Oh!” she said, “I thought it was Master Frederick. He didn’t sleep here last night, the naughty boy. I suppose he stayed the night with you or Master Larry - but he ought to have told me. When is he coming back?”

This was a real shock to Pip and Bets. So Fatty hadn’t come back from Milton House? What had happened?

“Oh! - he’ll be back today I expect,” Pip said to the anxious maid. He dragged Bets out into the garden. She was crying.

“Don’t be so silly,” said Pip. “What’s the good of crying before you know what’s happened to Fatty?”

“I knew something had happened to him. I knew he was in danger, I did, I did,” wept poor Bets. “I want to go down to Milton House and see what’s happened.”

“Well, you won’t,” said Pip. “There may be danger. You look after Buster for me. I’ll go down myself.”

“I’ll come too,” said Bets bravely, wiping her eyes.

“No, you won’t,” said Pip firmly. “I’m not going to have you running into danger. You don’t like danger, anyway. So you be a good girl and take Buster home with you. I’ll be back as soon as I can - and maybe I’ll bring Fatty with me, so cheer up.”

Still crying, poor Bets went off with the puzzled Buster, who simply could not understand what had happened to Fatty. He seemed to have disappeared into thin air!

Pip was much more worried than he had let Bets see. He couldn’t help thinking that something serious must have happened. But what could it be? Fatty would surely never allow himself to be caught. He was far too clever.

Pip went over the hill and down Chestnut Lane. He came to the gate of Milton House. He gazed in cautiously. He could see more footprints, and there were new car-wheel prints.

He went round the hedge, slipped in at a gap, and found himself by the summer-house. Inside were the rugs Fatty had taken to keep himself warm. But there was no Fatty there.

He stepped cautiously into the garden, and one of the men, who was watching, saw him from a window. He had with him the sheet of notepaper on which Fatty had written the two letters.

The man bent down, so that he could not be seen, opened the window a crack at the bottom, gave a loud whistle to attract Pip’s attention, and then let the paper float out of the window.

Pip heard the whistle and looked up. To his enormous surprise he saw a sheet of paper floating out of one of the second-storey windows. Perhaps it was a message from Fatty.

The boy ran to where the paper dropped and picked it up. He recognized Fatty’s neat hand-writing at once. He read the note through, and his heart began to beat fast.

“Fatty’s on to something,” he thought. “He’s found some stolen jewels or something and he’s guarding them. He wants us all to be in it! I’ll run back to the others, and bring them back with me. What an adventure! Good old Fatty!”

He scampered off, his face bright. The man watched him go and was satisfied. That young idiot would soon bring the other children down with him, and then they could all be locked up safely before they gave the game away!

Fatty saw Pip too and began to have a few horrid doubts. Were the Find-Outers smart enough to guess there was a secret letter in between the lines of inked writing? Suppose they didn’t? He would have led them all into a trap!

Pip ran all the way home. He was tremendously excited. What had Fatty discovered? It must be something very wonderful for him to be guarding it like that!

Bets was waiting for Fatty very anxiously. She was at the window of the playroom, and Buster was sitting on the window-sill beside her, his black nose pressed against the pane.

Pip grinned widely and waved the letter at Bets. She guessed at once that he had good news, and her heart felt lighter. She tore downstairs to meet him, Buster at her heels.

“Is Fatty all right? What has happened? Is that a letter from him?” she asked.

Pip pushed her upstairs again. “Don’t yell questions at me like that!” he said crossly. “You’ll have all the household knowing about our mystery soon!”

Just then the luncheon gong sounded, and Pip’s mother put her head in at the door. “Come along,” she said. “Don’t keep me waiting, Pip, because I have to go out immediately after lunch.”

So there was no time to show poor Bets the letter, and she was so terribly curious about it that she fidgeted all through the meal, much to her mother’s annoyance.

As soon as lunch was over, Pip and Bets flew upstairs, and Pip spread the note out on the table.

“Look there!” he said. “Fatty’s found something marvellous - and he’s guarding it. He wants us all to go down and join him. So we’d better go up to Larry’s and get him and Daisy as soon as we can.”

Bets read the note. Her eyes sparkled with excitement. This sounded too thrilling for words.