Things began to happen very quickly after this, and, quite suddenly, the Five Find-Outers found that there was a first-class mystery for them to solve.

The next afternoon Pip's mother, Mrs. Hilton, went to tea with Lady Candling, who was now back again next door after a short holiday.

"You may all have a picnic tea in the garden," she told Pip. "Daisy, see that everyone behaves, please, and if you haven't enough to eat, go and ask Cook politely — politely, remember — for some more bread-and-butter."

"Yes, Mrs. Hilton. Thank you very much," said Daisy. The children watched Pip's mother going down the drive at half-past three that afternoon, looking very smart. They were glad that they did not have to dress up and go out to tea. It was much more fun to have a picnic tea and wear old shorts and shirts!

They had a lovely tea, and went in twice to ask Cook for some more bread-and-butter. Daisy went, and remembered to ask very politely. There were ripe plums and greengages as well to eat, so it was a good tea.

Soon after tea Mrs. Hilton came back. She went straight to the children, looking rather worried.

"Children," she said, "what do you think has happened? That lovely prize-cat, called Dark Queen, has disappeared! Lady Candling is very upset, because she is most valuable. And the dreadful thing is — Luke may have stolen her!"

"Mother!" said Pip indignantly, "Luke's our friend. He would never, never do a thing like that!"

"He wouldn't, he wouldn't!" cried Bets.

"Oh, Mrs. Hilton," said Fatty earnestly, "I really don't think you are right in saying that Luke did that!"

"I didn't say he had" said Mrs. Hilton. "I said that he might have. All the evidence points to the fact that he was about the only one who could have done so."

"But he couldn't, he simply couldn't," said Daisy. "He's as honest as the day. It is much more likely to have been that hateful old Tupping."

"Tupping has been out all the afternoon with Mr. Goon the policeman, who appears to be his friend," said Mrs. Hilton. "So it is quite impossible that he could have stolen her."

The children stared at Mrs. Hilton, feeling upset and puzzled. Fatty took command of the whole affair, and spoke politely to Mrs. Hilton.

"Luke is a very good friend of ours, Mrs. Hilton, and if he is in trouble we must help him. I am quite sure he had nothing to do with Dark Queen disappearing, nothing at all. Could you please give us the whole story? This looks like something the Five Find-Outers can tackle again."

"My dear Frederick, don't talk so pompously," said Mrs. Hilton rather impatiently. "And don't start interfering in this matter, for goodness' sake. It's nothing to do with you. Just because you solved one mystery quite well is no reason why you should think you can interfere in anything else that crops up."

Fatty went red. He didn't like being ticked off in public like that.

"Mother, please do tell us all that has happened," said Pip.

"Well," said Mrs. Hilton, "Miss Harmer went off for the day this morning, after feeding all the cats and cleaning out their cages. Dark Queen was in the big cage with the other cats today. Miss Harmer went to catch the ten o'clock bus. Miss Trimble went with Lady Candling to see that the cats were all right at just before one o'clock, and Tupping pointed out Dark Queen to them. You know what a beauty she is."

The children nodded. "Go on, Mother," said Pip. "Was that the last time that anyone saw Dark Queen?"

"No," said his mother. "Miss Trimble went with me to show me the cats at four o'clock, just before tea — and Dark Queen was there then, in the cage with the others."

"How do you know, Mother?" asked Pip. "How could you tell which was Dark Queen? They are all exactly alike."

"I know," said Mrs. Hilton, "but apparently Dark Queen has been bitten on the tail, and a few hairs there grew cream instead of dark-brown. Miss Trimble pointed out the cat to me and I remember noticing the ring of creamy hairs — most noticeable. So she was in the cage, quite safe, at four o'clock."

"Go on," said Pip.

"Tupping came back at five o'clock and he brought Mr. Goon the village policeman with him," said Mrs. Hilton. "He showed Mr. Goon his prize tomatoes, and then he showed him the cats. Then Mr. Tupping suddenly noticed that Dark Queen was missing!"

"Gracious!" said Fatty. "Then the cat must have disappeared between four and five o'clock, Mrs. Hilton."

"Yes," said Pip's mother. "And as Luke was the only one in the garden, I am afraid that he is suspected. He knew that the cat was worth a lot of money. Tupping says that the boy stole something the other day too — strawberry runners or something silly like that."

Bets went fiery red. Tears came into her eyes. Those awful strawberry runners! She wondered if she should tell her mother about them, but Fatty frowned at her, warning her not to.

"Well, that's all," said Mrs. Hilton, pulling off her gloves. "But I'm afraid your friend Luke is in for trouble now. I wonder where he took the cat. No one seems to have seen Luke between four and five o'clock, so I suppose he could have put her into a basket and taken her off anywhere."

"Mummy, Luke wouldn't!" burst out Bets. "You don't know how kind and honest he is. He gave me a lot of whistles he made — and this lovely model of Dark Queen too. Look!"

"I wish you wouldn't make such extraordinary friends," said her mother, not looking at the model at all. "You are none of you old enough to know whether anyone is really honest or not. Please don't talk to Luke any more."

Mrs. Hilton went towards the house and disappeared indoors. The children looked at one another in dismay.

"It's just no good to say, 'Don't talk to Luke any more,' " said Fatty. "We've simply got to. He's our friend, and he's helped us lots of times — and Buster too. We've got to help him now."

All the others agreed. They sat and thought about everything for a little, and then began to talk about it

"Somebody must have stolen Dark Queen, there's no doubt about that," said Fatty. "It seems as if it could only be old Luke; but we're all absolutely certain it isn't, so who else could it be?"

"Let's look for clues!" said Bets eagerly, remembering how exciting it had been to look for clues in the last mystery they had solved.

"Let's draw up a list of Suspects!" said Daisy. "We did that before."

"Now," said Fatty importantly, "it seems to me that the Five Find-Outers can really get to work again. I propose...."

"Look here," said Larry, "you're forgetting something, Fatty. I'm head of the Find-Outers, not you."

"All right," said Fatty, looking sulky. "Go ahead then. Only I've got far more brains than you have. I was top of my form last term, and...."

"Shut up, Fatty," said everyone together, except Bets. Fatty looked as if he was going to get up and go; but he was too excited and interested to be sulky for long, and soon the five children were eagerly discussing their plans.

"Now, let's think everything out clearly," said Daisy.

"Dark Queen was with the others until four o'clock, because it was then that Miss Tremble and Pip's mother saw her. She wasn't there when Clear-Orf and Tupping went to see them at five. So, in that hour, somebody must have gone to the cage, unlocked it, taken out the cat, locked the cage again, and gone off with Dark Queen, and either given her to someone else or hidden her away."

"Right," said Larry. "Very clearly put, Daisy."

"The next thing is: Who could have stolen the cat? Whom can we suspect?" said Pip.

"Well, I suppose Miss Tremble might have slipped down and taken Dark Queen out," said Fatty. "Not very likely, of course, because Miss Tremble, poor thing, is the kind of person who would have a fit if she even posted a letter without a stamp. She'd dream about it all night long! Still, we have to consider everyone who had a chance of stealing Dark Queen."

Larry pulled out a notebook. "I'll write the names down, he said. "Miss Tremble is one. What about Lady Candling?"

"She wouldn't steal her own cat, silly," said Daisy.

"She might," said Larry. "It might be insured against theft, you know. She would get a lot of money. You've got to think of all these things." He wrote down Lady Candling's name.

"Tupping?" said Bets.

Larry shook his head very regretfully. "No, Bets. I'd love to put his name down; but if he was with old Clear-Orf all the afternoon it's just no good suspecting him. What about Miss Harmer? Could she possibly have come back quietly and secretly from her day out and taken the cat? She knew how valuable Dark Queen was."

This was quite a new idea. Everyone thought of the plump, smiling Miss Harmer. She didn't seem at all the sort of person who would steal a valuable cat from her employer. Still — her name went down on the list of Suspects.

"We'll have to try and find out where Miss Harmer was between four and five o'clock today," said Pip.

"Who else is there?" said Daisy. "We've got Miss Tremble, Lady Candling, and Miss Harmer down. What about the cook and house-parlourmaid next door? They would have had a chance of going down to the cat-house and taking Dark Queen, wouldn't they?"

"I've never seen the cook or parlourmaid," said Pip. "None of us have. We'll have to find out about them too. Goodness, we've got quite a lot of suspected people after all! We'll have a lot of work to do!"

"The one person who is horrid enough to have done it is Tupping — and he's just the very one we can't even suspect," said Bets sadly. "Well, there aren't any more Suspects, are there?"

"We'll have to put old Luke down," said Larry. "I know we don't suspect him — but Tupping has accused him of the crime, so we'd better put him down. We can cross him out as soon as we like."

So Luke's name went down too. Poor old Luke! He always seemed to be in trouble.

"Let's go and whistle to him," said Larry. "He hasn't gone home yet, or he'd have whistled to us and told us everything."

So they went to the wall and whistled the special notes that they and Luke used for signalling to one another. But although they whistled and whistled, nobody came. Whatever could Luke be doing?