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!”