“Well - if I’ve put him on his guard - he’ll probably come racing down to Peterswood to see if his precious secret room is all right,” said Fatty. “So we may have set things happening. We’ll keep a very, very strict eye on Milton House from now on. If Mr. Smith does come down, we’ll be able to see him and find out what he’s like.”

“We can’t watch at night,” said Larry doubtfully.

“I can,” said Fatty. “My mother would never know if I’m in bed or not.”

“But, Fatty - you’d never dare to go down to Milton House in the dark of night!” said Bets, horrified. “It’ll be so cold - and pitch dark - and simply awful.”

“It won’t be dark,” said Fatty. “The moon is nearly full. And I shan’t be cold. I spotted a sort of tumble-down summer-house there in the garden, and I can take a couple of thick rugs and make myself comfortable.”

The others stared at him in awe. Not one of them would have liked to go down to Milton House alone at night.

“I’m perfectly fearless,” said Fatty, basking in their admiration. “Why, when I was two years old, I went -”

“Shut up!” said Larry and Pip. “You spoil everything when you start boasting.”

“Will you take Buster with you?” asked Bets.

“Don’t know,” said Fatty. “He’d be company. On the other hand, he might bark if any one came.”

“Do you know it’s snowing?” said Daisy suddenly.

So it was. The big white flakes came down silently. The children stared at them out of the window.

“This will mean I’ll have to be awfully careful not to give myself away by footprints,” said Fatty. “I shall have to try and creep in through the garden hedge. Anyway, I shall be able to see if any one has been to the house, because their footprints will show too!”

“Shall we pop down to Milton House now?” said Pip. “Just to see if anything is different?”

“No. We’ll go tomorrow,” said Fatty. “Our Mr. John Henry Smith isn’t likely to rush over today - but most likely he will tomorrow - and we may see some sign of him then. Let’s play a game now.”

So they played Happy Families, and roared at Bets when she forgot the game for a moment and asked Daisy if she had got “Mr. John Henry Smith” instead of Mr. Bones the Butcher.

“I feel as if our mystery is warming up a bit,” said Fatty, when he said good night to the others. “I shouldn’t be surprised if things begin to happen soon!”

Next morning the Five Find-Outers and Buster set off to Milton House. The snow was very thick, and they left the marks of their footprints behind them.

Pips and Bets had to pass Mr. Goon’s house to meet the others, and the policeman saw them. He wondered if they were doing something he ought to know about. He felt so certain that the children were on the track of some mystery, and old Clear-Orf couldn’t bear the idea of their getting in first again.

He decided to follow them. He couldn’t very well ride his bicycle in the thick snow, so he set out on foot, keeping them in sight, but trying not to be seen himself.

However, as soon as Pip and Bets joined up with the others, Buster knew they were being followed. He stopped and growled, looking back along the road. The children turned too, and caught sight of the familiar dark-blue uniform slipping into a gateway.

“It’s Clear-Orf following us,” said Fatty, in disgust. “What a nuisance he is! We can’t possibly go to Milton House with him hard on our heels all the time. What shall we do?”

“We’re not very far from my house,” said Larry. “Shall I slip in and write a note of some sort that will make him think we are solving a mystery - but not the one we really are in the middle of? A make-up one?”

Every one giggled.

“Yes,” said Fatty, “and we’ll drop it behind us for him to pick up! I bet he’ll pounce on it and read it - and then he’ll be properly on the wrong track! Maybe he will give up bothering us then.”

So Larry popped in at his gate and wrote a hurried note in pencil:

“DEAR FATTY, - Just to tell you that I am on the track of the robber who stole those jewels. Meet me on Felling Hill, and I will show you where he hid the things before he took them away again. - Yours, L.”

Larry grinned as he stuck up the envelope. He ran out to the others, and they set off down the road again, hoping that Mr. Goon was still watching them.

Fatty laughed when Larry told him what he had written.

“Good!” he said, “now old Clear-Orf will think we are tracking a jewel-thief, and he’ll hare off to Felling Hill and do a bit of exploring there. Keep him quiet for a bit!”

“There he is - behind that tree,” said Bets. “Don’t look behind, anybody. You two boys begin to push one another about, and then drop the note as you do it. Clear-Orf will think you really did drop it by accident then.”

“Good idea, Bets,” said Fatty, approving. “You’re getting to be quite a good detective.”

The children set off again, and when they thought they were nicely in view of Clear-Orf they began to jostle one another, as if in play.

Larry and Fatty tried to push each other off the kerb, and in the middle of the tussle Larry dropped the note. Then the five children, with Buster, went on their way again. Buster nearly spoilt things by running back to the note and sniffing at it.

“Buster! Idiot! Come here and leave that alone,” said Fatty, in a low voice. “Don’t you dare to pick it up and bring it!”

Buster, though surprised, had the sense to leave the note where it was. Limping badly, he went after the others, feeling rather hurt that Fatty should have scolded him.

“Can we manage to see if old Clear-Orf picks it up?” said Larry excitedly. “I do hope he does.”

“I’ll go into the sweet-shop and watch, whilst you others go on,” said Fatty.

So Fatty watched from the sweet-shop, whilst he was buying chocolate, and to his great delight he saw Mr. Goon pick up the note!

“I bet he’ll read it!” thought Fatty, pleased. “He’s so jolly snoopy.”

Mr. Goon put the note in his pocket. He certainly meant to read it! He pondered whether to go on following the children or to slip home and read the note. It might tell him something he wanted to know!

He went home. He opened the note and gave a snort. “Ho! Didn’t I know they were up to something? On the track of some thief now. I suppose it’s the Sparling Robbery they’ve heard about. Well, who would have thought the thief would have come in this direction? Felling Hill, they say. Well, I’ll be along there sometime or other, and if I don’t sniff something out, my name’s not Theophilus Goon!”

Mr. Goon felt very pleased. “Those children think they’re clever - but they go and drop a note like this and give their game away,” thought the policeman. “Now I know what they’re after. I knew they were interfering in something again. Can’t keep them children out of meddling!”

He sat and thought for a moment. “Now wait a bit - this boy Larry says the thief put the things on Felling Hill and took them away again. Where did he take them to? Why are those kids so interested in Milton House? Ah - now I’ve got it - the thief has hidden the jewels somewhere in that empty house!”

This wasn’t at all what Larry had wanted Mr. Goon to think. But Mr. Goon felt very pleased with himself. He thought he could see everything clearly now. Somehow those kids had got on the Sparling Robbery mystery, and somehow they had got on the track of the thief, and had found out where he had first hidden his booty. Now they were on the track of the booty again - and maybe Milton House was the key to the mystery!

“Ah! - I’ll keep a good watch on that there house now,” he thought. “If there’s any jewels hidden there, I’ll be the one to find them and not that fat boy. Got brains, has he - but mine are better than his. Ho! I’ll pay him out for saying mine want oiling!”