“Come along, then,” said the Inspector, getting out his gun again. “You others keep back. Only Frederick is to come, to show me the way. You keep back when I open the cellar door, Frederick.”

Fatty proudly led the way to the cellar door, and produced the key from his pocket. From below came a violent voice, shouting and yelling, and now and again the sound of falling coal as poor Clear-Orf tried to find a way out.

The voice sounded vaguely familiar to Fatty as he gave the key to the Inspector to open the door. The Inspector put it in the lock and turned it.

“Come on out!” he roared. “Up the steps, man, and put your hands up!”

Some one came tumbling up the steps. It was poor Mr. Goon, without his helmet, which was lost somewhere in the coal, and as black as a negro. He stumbled out of the door, blinking in the bright torch-light shone on him by the Inspector. He was so dirty and black that neither Fatty nor the Inspector recognized him.

Mr. Goon was angry, afraid, and puzzled. He walked through the kitchen, with the Inspector prodding him from behind, and gaped to see the crowd of men in the hall. He also gaped to see the children there, opening and shutting his mouth like a goldfish.

Buster was the only one who recognized poor Mr. Goon. With a torrent of loud barks he flung himself joyfully at the ankles of his enemy.

“You clear-orf!” said Goon angrily, and kicked out at the dog. “What’s all this-ere?”

“It’s Clear-Orf!” cried all the Five Find-Outers in the greatest surprise.

“Goon!” said the Inspector, also in the utmost astonishment. “How did you - how is it - what has...” But the Inspector didn’t finish. Instead he burst out into such hearty laughter that the other members of the Squad grinned too.

“Well, Goon, this is an extraordinary meeting,” said the Inspector, eyeing the dirty, angry policeman with amusement. “I called at your place to find out if you knew anything about the goings-on here - but you were not there.”

“I were locked up in that filthy coal-cellar!” said Goon, and he glared at Fatty. “And that’s the one who locked me in! He wants watching, he does. He’s a Frenchy fellow, up to no good - in with the thieves, I don’t doubt - or whatever these fellows are you’ve caught. Wait till I get my hands on him!”

“Don’t you know me, Mr. Goon?” said Fatty, in his ordinary voice, and Mr. Goon jumped. He stared at the black curly wig, the big eyebrows, the sticking-out teeth - the face of that “Frenchy fellow,” not a doubt of it, but the voice was Fatty’s.

“I don’t think I want you to molest this helper of mine,” said the Inspector smoothly. “I’m surprised that a smart policeman like you, Goon, didn’t see through Master Frederick’s disguise!”

Fatty snatched off wig and eyebrows and with a little more difficulty removed the teeth. Mr. Goon stared and swallowed violently several times. He became deep purple. The six prisoners watched Fatty in amazement. The other Find-Outers giggled. Good old Fatty!

“We will leave any more explanations till later!” said the Inspector. “Now - lead the way, you men. There’s room in the police car for the prisoners and three guards. You others can get over to the aeroplane and stand guard there till relieved.”

The company dispersed. Mr. Goon, looking queer without his helmet, stood looking sulkily on.

“Better get home, Goon,” said the Inspector. “You look bad.”

“I feel bad,” said Mr. Goon, in a most aggrieved tone. “Didn’t I know those kids were interfering again? And then, just as I was finding out things, didn’t that boy go and lock me up so that he could get all the credit?”

“I didn’t know it was you Mr. Goon,” said Fatty truthfully.

“Wouldn’t have mattered if you had known. You’d have done it just the same!” said Mr. Goon. “Proper lot of nuisances you are, see? Messing about. Interfering with the Law.”

“No, no, Goon - helping the Law!” corrected the Inspector. “We’ve done a good night’s work here - caught nearly the whole gang of international thieves and their agents. You’ve heard of the notorious Finnigan, I have no doubt, Goon - and the equally infamous Lammerton? They are the men who specialize in procuring valuable pictures, jewels, china, and so on - and ship them to other countries to sell them!”

“Coo, yes, sir,” said Goon, his eyes nearly dropping out of his head. “Don’t mean to say we got them, sir! Coo - to think they’ve been meeting here under my very nose, like!”

“Yes - your nose must do a little better in future, Goon,” said the Inspector.

“A-TISH-OO!” sneezed Goon. “Well, sir - a-TISH-OO!”

“Go home, Goon, and get to bed,” said the Inspector. “You’ve got a bad cold.”

“Yes, I have,” said Goon, wiping his nose with a tremendous pocket-handkerchief. “Oughtn’t to be up at all by rights, but I felt it was me duty, sir, when I knew there was queer goings-on here, like. Thought I’d better risk getting pewmonia than neglect me duty, sir.”

“Very noble of you, Goon,” said the Inspector gravely. “Now get back home. I’ll have a talk with you tomorrow.”

Goon disappeared into the night, sniffiing and sneezing. He gave Fatty one last spiteful look, but Fatty didn’t mind. Buster gave Mr. Goon a few parting barks.

“And now,” said the Inspector, “do you think, Pip, that your good mother would let me share your supper? I have a feeling that she may like to hear a little of all this - I hope you agree with me?”

“Oh yes!” said Pip joyfully. He had been wondering how to explain everything to his mother and father. He knew his mother liked and admired the Inspector. Now things could all be straightened out, and there would be no scoldings for anything.

It ended in being a big supper-party, and a most enjoyable one. When Pip’s mother heard that something extraordinary had happened, and that the Inspector felt very pleased with the Five Find-Outers once again, she telephoned to Fatty’s parents, who were now back, and to Larry’s, asking them to come down and join them in supper that night.

The children all stayed up too, and the conversation was most interesting. The grown-ups listened in amazement to the tale of the third mystery, and though Pip’s mother secretly thought she really didn’t like Pip and Bets being mixed up in such queer doings, she didn’t say so.

Fatty, of course, was the hero of the evening. His description of secret writing, getting out of locked rooms and wearing disguises was listened to with the utmost astonishment.

“Well, really, Frederick!” said his mother. “I had no idea you were doing all these things. I didn’t even know you knew about them!”

“Well, Mother - you see I’ve been studying detective methods lately,” said Fatty. “I can’t help thinking I have a gift that way, really. I hope you won’t insist on my going in for soldiering, because I’m sure I should be wasted in the army. I’m a born detective, I could tell you things you could hardly believe. Why once -”

“Shut up!” said Pip, unable to bear Fatty’s vanity any longer. “You’re jolly clever at times, I agree; but, after all, it was me climbing that tree that first set us on the track of the Mystery of the Secret Room. You know it was.”

“You all deserve praise,” said the Inspector, beaming round. “Yes, even little Bets here, who was clever enough to smell the orange juice in that note of Frederick’s - and stopped the whole of the Find-Outers from walking into a trap!”

Bets went red. It was tiresome being the youngest Find-Outer, but it was lovely to be praised by the Inspector.

It was a happy and exciting evening. Nobody wanted to go home or go to bed. The Inspector left first, when his car came for him.

“Good night,” he said, “and many, many thanks for solving this mystery. I hope there will be many more for you to solve. I shall always appreciate your help, if I may say so!”