The torch flashed into Fatty’s face again.

“You know me?” said Inspector Jenks’ voice. “Who are you?”

The Inspector did not recognize Fatty in his curious disguise. Also Fatty was now extremely black and dirty, and looked more like a negro than himself.

“I’m Frederick Trotteville,” said Fatty. “I’m - er - disguised, Inspector, that’s all.”

“Quiet, now,” said the Inspector, and pulled Fatty into a field beyond the hedge. “Talk in a whisper. What are you doing here? The others telephoned to me and told me enough to puzzle me. I can’t say I thought very much of their story, but I came over to see what was up.”

“Good!” said Fatty. “The others guessed then that I had written a secret message, and they read it.”

“Yes,” said Inspector Jenks. “Well, as I said, I came over as soon as I could by car, and after I had heard what the others had to say, I went to see Mr. Goon. I wanted to see if he knew anything about this, because it was quite likely he did, and hadn’t told you.”

“Oh!” said Fatty. “We didn’t want Clear-Orf to know about it.”

“Well, he doesn’t,” said Inspector Jenks. “He wasn’t there, and no one knows where he is. Do you?”

“No,” said Fatty, not dreaming that Mr. Goon was well and truly locked into the coal-cellar of Milton House.

“Then I thought I’d come along down to Milton House myself,” said the Inspector, “and I bumped into you. What has been happening, Frederick? Is it really something serious, or just a little local robbery or something?”

“I don’t know what it is, sir,” said Fatty. “I really don’t. I can’t make it out. I’ll tell you what I know.”

So the boy related everything: he told of the secret room he had been locked in - the two men he had seen - the one he hadn’t seen, called Jarvis - the coming of the aeroplane, bringing more men to meet in the secret room - and how he had locked somebody into the cellar.

“So you’ll catch one of the men, anyway, sir,” he said, “even if the others escape. Oh! - I nearly forgot - I - er - I managed to get hold of this book for you to see. I thought it might tell you something. I don’t understand a word of it.”

By the light of his torch Inspector Jenks examined the queer little notebook that Fatty had taken from the cupboard in the secret room. He whistled.

“Yes - I understand this all right!” he said, and Fatty heard the real excitement in his low voice. “This is a code-book containing the names, both true and false, of members of a well-known gang and their various addresses! Pretty good work on your part, Frederick. Now, look here, you scoot up to the nearest telephone, ring the number I tell you, and say I want all the Squad down here immediately. There’s not a moment to spare. Immediately! Understand?”

Fatty understood. He felt thrilled. The other mysteries he and the Find-Outers had solved had been exciting, but really, this one was the most exciting of the lot. He shot off up the lane, leaving the Inspector to do a little more watching.

He got the number immediately. It was evidently a private police number. He gave his message. A sharp, commanding voice answered him:

“Right! Over in about ten minutes’ time.”

Fatty rang off. His heart beat fast. What should he do now? Surely he must go down and see what was going to happen? It promised to be extremely exciting.

On the other hand, would it be fair to leave the other Find-Outers out of this? They would so love to be in it too. Surely there wouldn’t be any danger if they all kept in the lane?

Fatty sped off to Pip’s. By good luck all the other Find-Outers were there, very worried, but very glad to think that Inspector Jenks had come and taken charge of things.

Buster suddenly began to bark his head off, and Bets knew that Fatty was coming up the stairs. She ran to the door, flung her arms round him, and dragged him into the room.

“Fatty! Are you safe? How did you get out? Oh, Fatty, we were so worried about you!”

“Get me some biscuits or something,” said Fatty. “I’m starving. You needn’t have worried about me. I was perfectly all right.”

“You look simply awful!” said Pip. “Black and dirty and really disgusting!”

“Don’t care,” said Fatty, and gobbled down some biscuits. “Had the time of my life. I’ll tell you all about it as we go.”

“Go?” said Daisy. “Go where?”

“Down to Milton House to see the fun,” said Fatty. “I’ve just telephoned for a squad of armed policemen to come over - Inspector Jenks’ orders!”

There were squeals and gasps. The other Find-Outers stared at Fatty with amazed eyes. Buster tried in vain to get on his knee. He was overjoyed at having Fatty again.

“Is it - is it dangerous?” asked Bets.

“Very - but not for us!” said Fatty. “Now do you want to come or not? I’ll tell you everything on the way. We must go at once or we shall miss the fun.”

They went, of course. They flung on hats and coats and trooped out into Pip’s drive, excited. They set out over the hill, and just as they got to the other side a powerful police car swept by them!

“That’s it - that’s the armed Squad!” said Fatty. “Did you see them? My, they’ve been quick!”

The big police car roared down Chestnut Lane, and the children hurried as fast as they could after it. Their hearts thumped, and Bets clung tightly to Fatty’s sturdy arm. Buster, his tongue hanging out, his tail wagging all the time, hurried along too, quite forgetting to limp in his excitement.

They arrived at the gateway of Milton House. The police car was outside in the lane. Black shadows here and there showed where members of the Squad were. Orders were being given by the Inspector in a low voice.

“He’s putting men in a ring round the house,” whispered Fatty to the others, almost choking with excitement. “See - there goes one that way - and there’s another going the other way round the house. I wonder how they will get in.”

Inspector Jenks had a very simple way of getting in. He had read Fatty’s letter to the Find-Outers, and had noticed that he had told them to knock at the door.

So, if he or his men walked up the steps to the door and hammered with the knocker, the men inside would quite probably think it was the children coming along in obedience to Fatty’s letter.

When all his men were in position around the house, the Inspector went to the front door and lifted knocker. All the children jumped when they heard the loud rat-a-tat-tat.

The door opened wide. Evidently the one who opened it - probably Jarvis - expected four children to walk quietly in.

Instead of that a burly figure crowded on top of him, the round barrel of a revolver was pressed into his chest, and a low voice said, “Not a word!”

Immediately on the Inspector’s heels came three more men. The door was quietly shut. Then one of the men put handcuffs on the frightened Jarvis.

The Inspector went silently up the stairs followed by two of his men. They all wore rubber-soled shoes and made no sound at all. Right up to the top of the house they went, to a room where light came from the keyhole. It was the secret room.

The Inspector swung it open suddenly, his revolver in his hand. He said nothing at all. There were five men in the room, and they all leapt to their feet at once. One glance at the Inspector’s stern face, and they put up their hands.

Then the Inspector spoke, in quite an amiable voice, looking round the room.

“Ah! - got yourself a cosy little nest here, haven’t you? Pleased to see you again, Finnigan - or is your name John Henry Smith now? And you’re here too, I see, Lammerton - well, well, well, this is an unexpected pleasure, if I may say so!”

The two men spoken to scowled. One was the thin-lipped man, and the other was the red-faced man. The Inspector looked at the others.

One of them spoke eagerly. “I’m not in this Inspector! I didn’t know till tonight, when I was brought over here by plane, that there was any dirty work afoot.”

“Really?” said the Inspector disbelievingly. “You hadn’t got anything unusual in the way of antiques to sell, I suppose? Oh no - you don’t know anything about the theft of the priceless Chinese vases owned by the Belgian Count, I suppose? You are quite innocent!”

“And you!” he said, turning to another man, “you hadn’t anything to do with getting the valuable picture from the Paris gallery, had you? You don’t know anything about that, I’m sure! Well, well - I can only say it is unfortunate that such clever and notorious rogues as you should be found here, in a secret place, with equally well-known buyers of antiques, rogues too, known to be hand in glove with the same kind of fellows on the other side of the Atlantic!”

“The game’s up,” said the fifth man, in a sulky voice. “I always said this was a dangerous place to meet in.”

“It’s been all right up till now, hasn’t it?” said the Inspector. “A very nice quiet spot! A good place to meet and to plot - a good place even to store valuable goods until the hue and cry has died down, and you can take them over to America to sell. Barred windows to protect your goods and all! A good many police all over the world have been on the look-out for your clever gang for years. I am happy to think it will be broken up for a long time to come!”

The other men who had come up with Inspector Jenks moved into the room and deftly put handcuffs on each of the five sullen men.

“Any more of you?” inquired the Inspector. “We’ve got a fellow downstairs.”

“Find out for yourself,” said Lammerton viciously.

“We will,” said the Inspector. “There are men all round the house, as you will probably guess. A very proper precaution, as I am sure you will agree?”

The men scowled and said nothing. The Inspector gave a sharp order, and every one went out of the room. For a minute or two Inspector Jenks examined the secret room, his eyes sharp and shrewd. Then he went downstairs too.

The five men and Jarvis were lined up in the hall. One of the policemen had put a lantern on a ledge and the scene was lighted up. The five children at the gate, feeling certain that things were safe now, crept up to the door and looked in.

“Golly! “ said Larry, in awe. “Look at them all - what scoundrels they look! What are they, Fatty, do you think? Thieves? Spies? Or what?”

“They might be anything,” said Fatty, squinting in. “They look bad enough!”

Suddenly Fatty slipped and fell, making a slithering noise. At once the front door was flung open and a policeman looked out.

“Who’s there?”

“It’s only us,” said Fatty, grinning up into the beam thrown by the torch. “Hallo, Inspector - we just came to see the fun.”

“Then you’ve no right to,” said the Inspector. “There might have been shooting. Frederick, which of these men did you see most of?”

Fatty pointed to the thin-lipped man and the red-faced one. “Have you got them all?” he said. “What about the one I locked into the coal-cellar?”

The prisoners looked astonished. The thin-lipped man spoke sharply to Fatty.

“How did you get out of that locked room?”

“I don’t give my secrets away,” said Fatty. “Inspector, the one in the cellar makes seven. Shall we get him?”

“There’s nobody else.” said the thin-lipped man. “Only six of us.”

Another black figure loomed up in the darkness outside and a policeman came into the light.

“Sir,” he said to the Inspector, “there’s someone underground somewhere. I was standing on guard at the back there, and I kept hearing muffled shouts, but couldn’t make out where they came from.”

“That’s the fellow I locked in the coal-cellar!” said Fatty. “Let’s go and get him!”