"And yet his chauffeur met the London train and he walked off it!" said Daisy. "He couldn't possibly have seen the planes if he was really on the train, because at that time the train had hardly started out from London!"

"And so," said Fatty, a note of triumph in his voice, "and so, Find-Outers, we have yet another Suspect. Mr. Hick himself!"

"Oooh," said Bets, amazed. "But he wouldn't fire his own cottage!"

"He might — to get the insurance money on his valuable papers," said Fatty. "People do that sometimes. I expect he sold the papers — then set fire to the workroom and pretended the papers were burnt., in order to get more money. Golly! Can it really be possible?"

"We can't tell any one," said Daisy.

"I should think not!" said Larry. "Whatever in the world shall we do about it?"

"We must find out how it was that Mr. Hick got on the London train that night," said Fatty. "Look — we're near the railway line here. The London trains always come by here, and there's one due. Let's see what happens."

The children climbed on to the fence by the railway and sat there, waiting. Soon they saw a cloud of smoke in the distance. The train was coming. It came roaring along — but when it reached one portion of the line, it slowed down, and finally it stopped.

"It always stops there," said Bets. "I've noticed that. Perhaps it gets water or something."

It was too far away to see why it had stopped. Anyway it soon started up again, and puffed by the five children. Buster ran away behind a bush when it came. He was afraid of the noise.

Fatty was again thinking very deeply. So was Larry. "Listen," said Fatty. "Is it possible for any one at night to wait for the train just there, and hop into an empty carriage, do you think? Then, at Peterswood Station, if he had a season ticket, people would never know he hadn't come all the way from London."

"Fatty, I believe you're right!" said Larry. "I was just thinking the very same thing myself. I believe Hiccup could have done it. Pretended to go to London — slipped back — hid in the ditch, leaving those few footprints behind him — fired the cottage — slipped back to the railway line just there — waited till the train stopped, as it always does — hopped into an empty carriage in the dark — and then got out as cool as a cucumber, to be met by his car and chauffeur at the station!"

The more the children thought about this, the more certain they felt that Mr. Hick might have done it. "After all," said Bets, "A man that could break his faithful promise could do anything, simply anything."

"Whatever is Buster doing?" said Fatty, hearing some excited barks coming from the little dog, some way back in the copse of trees behind them. "Buster! BUSTER! What's the matter? Found a rabbit?"

Buster yelped and then appeared, dragging something black and muddy. "Whatever has he got?" said Bets.

Every one looked to see. "It's an old shoe!" said Daisy, laughing. "Buster, what do you want with an old shoe?"

Buster went to Bets and laid the shoe down at her feet. Then he stood looking up at her, as if he was telling her something, wagging his tail hard. Bets picked up the shoe. She turned it over.

"Look!" said Bets. "The real proper shoe at last! The one that made the footprints!"

The others nearly fell off the fence in their excitement. Bets was perfectly right. It was THE SHOE!

"Buster followed the footprints and knew their smell, and when he smelt the shoes hidden over there he knew the smell again, and that's why he brought them to me" cried Bets. "We had followed the prints together, you see. Oh, and now I know why he kept on and on sniffing round Mr. Hick's shoes when I went to see him. He could smell the same smell!"

"Clever dog," said Fatty, patting Buster. "Where's the other shoe, old fellow? Find it, find it!"

Buster rushed off to a bush not far away and began to scrape violently beneath it. Soon he unearthed the other shoe and laid it at Fatty's feet. The children picked it up.

"Well!" said Fatty. "This is very queer. I suppose old Hiccup got the wind up after Bets had told him she had followed the footprints, and went out and buried the shoes in case the police should find them in his house, or spot him wearing them. And good old Buster smelt them out. Clever good, marvellous dog! Big bone for you tomorrow, Buster., a GREAT BIG BONE!"

"And now — whatever are we going to do about everything?" said Larry, going back to the path. "It's no good telling the police. We're in disgrace and wouldn't be listened to. It's no good telling our parents. We're in enough trouble as it is."

"Let's go and sit down by the river and talk about it," said Pip. "Come on. We'll simply have to decide something. Things are getting very serious."

The children made their way along the path that led to the river. They found a sheltered place on the high bank of the river and sat down. Buster growled a little but sat down with them.

"What are you growling for Buster?" said Bets. "Don't you want to sit down?"

Buster growled again and then stopped. The children began to talk.

"It's a queer thing," said Pip, "we've found the man who started the fire — and we've got all the facts — we know how he got on to the London train — we know that his shoes fit the footprints — we know that he was afraid and hid those shoes — which we've found — and we know why all the other Suspects were down in the garden that evening. We know everything — and yet we can't do anything about it because Mr. Goon would be sure to pretend that he found out everything!"

"Yes — it's no good telling the police," said Fatty gloomily. "And it's no good telling our parents either, because they would just ring up Mr. Goon. Isn't it perfectly sickening to think that we've solved the mystery and found out simply everything, and we can't get the criminal punished. Horrid Mr. Hick! He ought to be punished. Don't you think it was mean the way he tried to lay the blame on poor old Peeks when he thought we were getting to know too much?"

"Yes," agreed every one.

"It was funny the way he gave himself away by mentioning those aeroplanes," said Lany. "It was really smart of Fatty to spot that, I think."

"It certainly was," said Daisy warmly, and the others nodded.

Fatty swelled up at once. "Well, as I've told you before," he said, "I really have got brains. Now, at school…"

"Shut up, Fatty," said every one together, and Fatty subsided and shut up, still feeling pleased, however, that the others admired him for spotting such a curious clue.

They all went on talking about the burnt cottage and the Suspects and clues for a little while longer, and then Buster growled so fiercely and so long that every one was surprised and puzzled.

"What is the matter with Buster?" said Bets. "Has he got a tummy-ache or something, do you think?"

She had hardly finished saying these words when a large round face appeared above the rim of the high river bank. It was a kindly face, set with big intelligent eyes that had a real twinkle in them.

"Oh!" said every one, startled.

"Pardon me," said the face. "I'm afraid I've frightened you. But, you see, I was sitting down here, below the bank, in my favourite corner, fishing. Naturally I kept quiet, because I didn't want to disturb the fish. I couldn't help hearing what you were talking about — it was most interesting, most interesting, if you'll pardon my saying so!"

Buster barked so loudly that the children could hardly hear what the hidden person was saying. He climbed up on to the bank beside them, and they saw that he was a very big fellow, burly and strong, dressed in a tweed suit and enormous brown shoes.

The man sat down beside them and took out a bar of chocolate, which he broke into bits and offered the children. They couldn't help liking him.