Poor Fatty almost jumped out of his skin. "Oooh!" he said, frightened, and the shoe dropped from beneath his coat!

"Ho!" said a voice that Fatty knew only too well. "Ho!" A torch was flashed into his face, and the voice said "Ho!" again, this time more loudly.

It was Clear-Orf s voice. He had been standing quietly beside the tree, and had been astonished to see Fatty come up the lane, and walk softly up and down in front of the house. Now he was even more astonished to find that it was "one of them children!" He bent down and picked up the shoe. He stared at it in the greatest astonishment.

"What's this?" he said.

"It looks like a shoe," said Fatty. "Let me go! You've no right to clutch me like that."

"What are you doing with this shoe?" asked Clear-Orf, in an astonished voice. "Where's the other?"

"I don't exactly know," said Fatty truthfully. The policeman shook him angrily.

"None of your cheek," he said. He turned the shoe upside down and saw the rubber-sole. At once the same thought flashed across his mind as had flashed across Daisy's when she had first seen it — the markings were like those on the footprint!

Mr. Goon stared at the shoe in amazement. He flashed his torch at Fatty again. "Where did you get this?" he asked. "Whose is it?"

Fatty looked obstinate. "Some one found it and gave it to me," he said at last.

"I shall keep it for the time being," said Mr. Goon. "Now you just come-alonga-me for a minute."

But Fatty didn't mean to do that. With a sudden quick twist he was out of Clear-Orf s grasp and tearing up the lane as fast as he could go. He went right to the top, and then round and into the lane in which Larry's house stood. He slipped into Larry's drive when he came to it and made his way to the bottom of the garden, his heart beating loudly. He shinned up to the top of the wall and dropped down. He made his way cautiously to the back the house.

Then he hooted like an owl. "Oooo-oo! Oooo-ooo-ooo-OOOOO!"

In another moment poor Fatty almost jumped out of his skin again! Some one clutched his arm hard. He had been expecting an answering whistle or hoot from somewhere about, but he had not guessed that Larry was behind the bush that he himself was standing by.

"Oooh!" said Fatty, startled.

"Sh!" came Larry's voice in a whisper. "Have you got the shoe?"

"No," said Fatty, and explained quickly what had happened to it. Larry listened in dismay.

"You are an idiot!" he said. "Giving one of our best clues away to old Clear-Orf like that! He'll know we are after the same ideas as he is now!"

"The shoe wasn't a clue," argued Fatty. "It was a mistake. We thought it was a clue, but it wasn't. Anyway, Clear-Orf s got it, and I really couldn't help it He nearly got me too. I only just managed to twist away,".

"What shall we do?" asked Larry. "Shall we go in and hunt now? There's no light in the study. Old Mr. Smellie must have gone to bed."

"Yes, come on," said Fatty. "Where's the garden door?"

They soon found it, and to their great delight it was still unlocked. As there was a light from the kitchen, the two boys thought that Miss Miggle was still up. They decided to be very cautious indeed.

They slipped in at the door. Larry led the way to the study where he and Daisy had talked to Mr. Smellie that day. "You'd better stay on guard in the hall," he said. "Then if Miss Miggle or Mr. Smellie do happen to come along you can warn me at once. I shall open one of the windows of the study if I can do it without making a lot of noise — then I can slip out of it if any one thinks of walking into the room."

Larry went into the study. He had a torch with him, and he shone it round the untidy room. There were papers everywhere! Papers and books on the desk, papers and books on the floor and on the chairs. There were books in the bookcases that lined the wall, and books on the mantelpiece. It was quite plain that Mr. Smellie was a very learned man!

Larry began to hunt for the shoes he hoped to find. He pulled out a few books from each shelf in the bookcase and ran his hand behind. But there was nothing there. He looked under the piles of paper everywhere but he found no shoes.

Fatty was outside in the hall, keeping guard. He saw the hall-cupboard where Daisy had found the shoe, and he thought it would be a good idea to peep into it. Daisy might possibly have overlooked some shoes that might be the right one. He slipped into the cupboard.

He was so very busy turning up the shoes and boots in the cupboard that he didn't hear some one slipping a latchkey into the front door. He didn't hear some one coming into the hall and quietly closing the front door. So he had no time at all to warn poor Larry to escape! He only heard Mr. Smellie when the old man walked into the study and switched on the light!

It was too late to do anything then, of course! Larry was caught with his head inside a cupboard, not knowing that any one was in the room until the light was suddenly switched on!

He took His head out of the cupboard in horror. He and Mr. Smellie stared at one another, Larry in fright, and Mr. Smellie in anger and amazement.

"Robber!" said Mr. Smellie angrily. "Thief! Wicked boy! I'll lock you up and telephone to the police!"

He pounced on Larry and took hold of him with a surprisingly strong hand. He shook the boy hard, and Larry gasped. "Please, sir," he began, "please, sir."

But Mr. Smellie was not going to listen to anything. His precious papers were all the world to him, and the sight of somebody rummaging through them filled him with such fury that he was unable to listen to a word. Shaking Larry hard, and muttering all sorts of terrible threats, he pushed the boy before him into the hall. Poor Fatty, overcome with shame at having failed to warn Larry, shivered in the hall cupboard outside, not daring to show himself.

"Bad, wicked boy!" he heard Mr. Smellie say as he pushed poor Larry up the stairs. Larry was protesting all the time, but Mr. Smellie wouldn't listen to a word. "I'll fetch the police in. I'll hand you over!"

Fatty trembled. It was bad enough to be caught, but it was even worse to think that poor Larry might be handed over to that horrid old Clear-Orf. He heard Mr. Smellie take Larry to a room upstairs and lock him in. Miss Miggle, amazed at the sudden noise, came rushing into the hall to see what the matter was.

"Thieves and robbers!" cried Mr. Smellie. "That's what the matter is! I came home just now, walked into my study — and there I found thieves and robbers after my papers!"

Miss Miggle imagined that there must have been two or three men there, and she gaped in astonishment.

"Where are the robbers?" she asked.

"Locked in the box-room upstairs," said Mr. Smellie. Miss Miggle stared at Mr. Smellie in even greater surprise. She couldn't believe that he had taken two or three men upstairs by himself and locked them into the box-room.

She saw that Mr. Smellie was trembling with excitement and shock. "Now you just go and sit down quietly before you telephone the police," she said soothingly. "You're all of a shake! I'll just bring you something to drink. The robbers are safe enough upstairs for a bit."

Mr. Smellie sank down on a chair in the hall. His heart was thumping, and he was breathing hard. "Be all right in a minute," he gasped. "Ha! I got the best of the robbers!"

Miss Miggle ran to the kitchen. Fatty listened breathlessly. Somehow he felt certain that old Mr. Smellie bad gone back into the study. He didn't know that he was sitting on a chair just at the foot of the stairs.

"I'd better take this chance of rescuing poor Larry," thought Fatty, in desperation. He opened the cupboard door and made a dart for the stairs. Mr. Smellie was most amazed to see another boy appearing, this time out of the hall cupboard. He could hardly believe his eyes. Was his house alive with boys that night?