Mr. Goon, of course, was exercising his mind too, about the missing pearls. He too knew that if only he could spot Number Three, he might be led to the pearls. But he had not got as far as reckoning out that it would be a good idea to watch old Johnny again, to see if Number Three came to receive a message!

That afternoon four of the Find-Outers sat in the little sweet-shop, on the opposite side of the road to the bench where the old man so often sat. Fatty was not with them. He was leaning against a tree not far off, apparently deep in a paper, his bicycle beside him. He was watching for the old man to come. How he hoped he would!

The bicycles belonging to the others were piled against the side of the sweet-shop. The four children in the shop were eating ices, and watching the bench opposite as keenly as Fatty was.

Some one came shuffling round the corner. Hurrah! It was the old man, complete with sniffle and pipe and cough. He sat himself down gingerly on the bench with a little groan, just exactly as Fatty used to do.

Then he bent himself over his stick-handle and seemed to go to sleep. The children waited, whilst their ices melted in the saucers. Had Johnny got a message to deliver from Number Five to Number Three?

A noise made them jump violently. It was the sound of a hooter! Fatty jumped too. He lifted his head cautiously from his paper, and saw a man riding down the High Street on a bicycle.. It had a hooter instead of a bell.

The man rode to the bench, hooted, and got off his bicycle. He stood his machine against the kerb and went to sit down on the bench close to the old man.

The old fellow did not even look up. How would he know if it was Number Three or not then? He was deaf and would not hear a whisper. Fatty puzzled his brains to think.

"Of course!" he thought suddenly. "That loud hooter always tells the old man when Number Three is coming to sit on the bench beside him. Of course! Gosh, that's clever."

The old man took absolutely no notice of the other man. Fatty watched very carefully, but he could not see any movement of the old man's mouth, nor could he see the giving of any paper-message.

For a few moments the two men sat together, and then old Johnny sat up a little straighter, and began to draw patterns in the dust with the end of his stick. Fatty watched more carefully to see if the old man was talking, under cover of his movements. But he could not make out that he was—unless he could talk without moving his lips, as a ventriloquist can!

After a minute or two the other man got up and went to his bicycle. He got on it, hooted, and rode slowly over to the sweet-shop. The four children in there stiffened with excitement. What was he coming over there for?

Bets gave a gasp as he came in, and Pip kicked her under the table, afraid she might give them away. Bets took one look at the man and then began to finish her ice, making rather a noise with her spoon.

"Box of matches, please," said the man, and put a penny down on the counter. Nobody liked to look at him in case he became suspicious of them.

He went out, lighting a cigarette. "He's got odd eyes!" said Bets. "He's the one! Hooter on his bike—and odd eyes! Oooh—it's getting exciting."

Fatty, waiting by the tree outside, saw the man go in and out of the shop. The boy folded up his paper quickly, and mounted his bike as the man went swiftly by him. He followed him at a discreet distance, wondering if he had had any message, and if he was going to lead him to the pearls!

"Come on," said Larry, going out of the shop quickly. "We've got to follow too."

The man rode down to the Fair. He wandered round a bit and then went to the Hall of Waxworks. But he only just put his head inside, and came out.

Fatty popped his head inside too, but except that it was full of people looking at the waxworks, there was nothing different to see. Napoleon was dressed and back in his place, and the red-haired boy was relating an extraordinary tale of how, in the night, Napoleon had apparently got out of his place, undressed and put himself to bed in a cupboard.

"Story-teller!" said some listening children. "What a fib!"

"And what's more," said the red-headed boy, thoroughly enjoying himself, "that wax policeman over there—do you see him? Well, he got up in the night and went and stood himself behind that curtain. Such goings-on!"

Fatty longed to hear more of this, but the man he was following had gone, and Fatty had to go too, or lose him.

The man had put his bicycle beside the hedge and pad-locked the back wheel, so Fatty knew he meant to stay around for a while.

The other Find-Outers came up, and Fatty winked at them. "Looks as if we're going to spend an hour or two in the Fair!" he said.

The man wandered about most aimlessly. He didn't even have a ride on the roundabout, or try for a Hoopla gift, or go in a Bumping Car—he just trailed about. Every now and then he passed the Waxworks Hall, and looked inside. But he didn't go in at all. Fatty wondered if he was waiting for somebody to meet him there.

"I don't believe he knows where the pearls are!" thought Fatty. "Or surely he'd go straight to them! My word what a crowd there is at the Fair today!"

The man evidently thought the same. He asked a question about it of the man at the Hoopla stall. "Quite a crowd today I What's up?"

"Oh, it's a trip from Sheepsale, a kind of outing," said the man. "They're going at four o'clock, then the place will empty a bit. Good trade for us, though!"

The man nodded. Then he made his way through the crowd to his bicycle, and unpadlocked it. Fatty followed him. It was clear that the man couldn't do whatever he wanted to do, because the place was too crowded. Probably he would be coming back. It was up to Fatty to follow him. He would leave the others down in the Fair, because he was sure that he and the man would be back there sooner or later, when the trippers had gone.

He had time to give a quick message to Larry. Then off he went over the level-crossing on his bicycle, following the man as closely as he dared. Round the corner they went, the man hooting with his little hooter—parp-parp.

And round the corner on his bicycle came Goon! The two almost collided. Goon, who had heard the hooter, glued his eyes on the man at once. Was he Number Three? He must be! He seemed to be the only man within miles who had a hooter on his bicycle, instead of a bell, for some peculiar reason that Goon couldn't guess.

Goon made up his mind to follow Number Three at once, and keep him in sight. Visions of pearl necklaces floated in front of his eyes. Number Three knew where those pearls were, Goon was sure of it. Off he went after Number Three.

And behind him went Fatty, annoyed and angry. Was Goon going to get in first again! Goon heard some one behind him and turned. He scowled.

That fat boy again! Was he after Number Three too. "Gah!" said Goon to himself. "The interfering Toad!"