‘Yes, that’s a coward’s trick all right,’ said Mrs. Cockles’s cheerful voice. ‘You mark my words, Mrs. Moon, there’ll be more of those nonnimus letters, or whatever they calls them - those sort of letter-writers don’t just stop at the one person. No, they’ve got too much spite to use up on one person, they’ll write more and more. Why, you might get one next!’

‘Poor Gladys was right-down upset,’ said Mrs. Moon. ‘Cried and cried, she did. I made her show me the letter. All in capital letters it was, not proper writing. And I said to her, I said, “Now look here, my girl, you go straight off to your mistress and tell her about this. She’ll do her best for you, she will.” And I pushed her off to Mrs. Hilton.’

‘Did she give her her notice?’ asked Mrs. Cockles.

‘No,’ said Mrs. Moon. ‘She showed Mr. Hilton the letter, and he rang up Mr. Goon. That silly, fussing fellow! What do they want to bring him in for !’

‘Oh, he’s not so bad,’ said Mrs. Cockles’s cheerful voice. ‘Just hand me that broom, will you? Thanks. He’s all right if he’s treated rough. I don’t stand no nonsense from him, I don’t. I’ve cleaned for him now for years, and he’s never had a harsh word for me. But my, how he hates those children!’

‘Ah, that’s another thing,’ said Mrs. Moon. ‘When Mr. Hilton told him about this here letter, he was that pleased to think those kids knew nothing about it - and he made Master and Mistress promise they’d not let those five interfere. And they promised. I was there, holding up poor Gladys, and I heard every word. “Mrs. Hilton,” he said, “Mrs. Hilton, madam, this is not a case for children to hinterfere in and I must request you, in the name of the law, to keep this haffair to yourselves.” ’

‘Lawks!’ said Mrs. Cockles. ‘He can talk grand when he likes, can’t he? I reckon, Mrs. Moon, maybe there’s been more of these letters than we know. Well, well - so poor Gladys went home, all upset-like. And who’s going to come in her place, I wonder? Or will she be coming back?’

‘Well, it’s my belief she’d better keep away from this village now,’ said Mrs. Moon. ‘Tongues will wag, you know. I’ve got a niece who can come next week, so it won’t matter much if she keeps away.’

‘What about a cup of tea!’ said Mrs. Cockles. ‘I’m that thirsty with all this cleaning. These rugs look a fair treat now, Mrs. Moon.’

Bets fled as soon as she heard footsteps coming in at the scullery door. Her knitting almost tripped her up as she went. She ran up the stairs and into the playroom, panting. Pip was there, reading and waiting for her.

‘Pip! I’ve found out everything, simply everything!’ cried Bets. ‘And there is a mystery to solve - a kind we haven’t had before.’

Sounds of laughter floated up from the drive. It was the others coming. ‘Wait a bit,’ said Pip, excited. ‘Wait till the others come up. Then you can tell the whole lot. Golly, you must have done well, Bets!’

The others saw at once from Bets’ face that she had news for them. ‘Good old Bets!’ said Fatty. ‘Go on, Betsy. Spill the beans!’

Bets told them everything. ‘Somebody wrote a nonnimus letter to Gladys,’ she said. ‘What is a nonnimus letter, Fatty?’

Fatty grinned. ‘You mean an anonymous letter, Bets,’ he said. ‘A letter sent without the name of the sender at the bottom - usually a beastly cowardly sort of letter, saying things that the writer wouldn’t dare to say to any one’s face. So poor Gladys got an anonymous letter, did she?’

‘Yes,’ said Bets. ‘I don’t know what it said though. It upset her. Mrs. Moon got out of her what it was and made her go and see Mother and Daddy about it. And they rang up Mr. Goon.’

‘And he came popping along, his eyes bulging with delight because he’d got a mystery to solve that we didn’t know about!’ said Fatty. ‘So there’s an anonymous letter-writer somewhere here, is there? A nasty, cowardly letter-writer - well, here’s our mystery, Find-Outers! WHO is the writer of the “nonnimus” letters?’

‘We shall never be able to find that out,’ said Daisy. ‘How on earth could we?’

‘We must make plans,’ said Fatty. ‘We must search for clues!’ Bets’ face lighted up at once. She loved hunting for clues. ‘We must make a list of suspects - people who could do it and would. We must...’

‘We haven’t got to work with Goon, have we?’ said Pip. ‘We don’t need to let him know we know, do we?’

‘Well - he already thinks we know most of this,’ said Fatty. ‘I don’t see why we shouldn’t tell him we know as much as he does, and not tell him how we’ve found out, and make him think we know a lot more than we do. That’ll make him sit up a bit!’

So, the next time that the Five Find-Outers met the policeman, they stopped to speak to him.

‘How are you getting on with this difficult case?’ asked Fatty gravely.   It - er - it abounds with such strange clues, doesn’t it?’

Mr. Goon hadn’t discovered a single clue, and he was astonished and annoyed to hear that there were apparently things the children knew and he didn’t. He stared at them.

‘You tell me what clues you’ve found,’ he said at last. ‘We’ll swap clues. It beats me how you know about this affair. You wasn’t to know a thing, not a thing.’

‘We know much more than you think,’ said Fatty solemnly. ‘A very difficult and - er - enthralling case.’

‘You tell me your clues,’ said Mr. Goon again. ‘We’d better swap clues, like I said. Better help one another than hinder, I always say.’

‘Now, where did I put those clues?’ said Fatty, diving into his capacious pockets. He brought out a live white rat and stared at it. ‘Was this a clue or not!’ he asked the others. ‘I can’t remember.’

It was impossible not to giggle. Bets went off into a delighted explosion. Mr. Goon glared.

‘You clear-orf,’ he said majestically. ‘Making a joke of everything! Call yourself a detective! Gah!’

‘What a lovely word!’ said Bets, as they all walked off, giggling. ‘Gah! Gah, Pip! Gah, Fatty!’

Everyone went to tea at Fatty’s that day. Mrs. Trotteville was out, so the five children had tea in Fatty’s crowded little den. It was more crowded than ever now that Fatty had got various disguises and wigs. The children exclaimed in delight over a blue-and-white striped butcher-boy’s apron and a lift-boy’s suit complete with peaked cap.

‘But, Fatty, whenever could you disguise yourself as a lift-boy?’ asked Larry.

‘You never know,’ said Fatty. ‘You see, I can only get disguises that do for a boy. If I were a grown-up I could get dozens and dozens - a sailor’s suit, a postman’s, even a policeman’s. But I’m a bit limited, being a boy.’

Fatty also had a bookcase crammed full of detective stories. He read every one he could find.

‘I pick up quite a lot of hints that way,’ he said. ‘I think Sherlock Holmes was one of the best detectives. Golly, he had some fine mysteries to solve. I don’t believe even I could have solved all of them!’

‘You’re a conceited creature,’ said Larry, trying on the red wig. He looked very startling in it. ‘How do you put those freckles on that you had with this?’ he asked.

‘Grease-paint,’ said Fatty. ‘There are my grease-paints over there - what actors use for make-up, you know. One day I’m going to make myself up as a black boy and give you all a fright.’

‘Oh - do give old Clear-Orf a scare too!’ begged Bets. ‘Let me try on that wig, Larry; do let me.’

‘We really ought to be making our plans to tackle this mystery,’ said Fatty, taking a beautiful gold pencil out of his pocket. Pip stared.

‘I say! Is that gold?’

‘Yes,’ said Fatty airily. ‘I won it last term for the best essay. Didn’t I tell you? It was a marvellous essay, all about...’

‘All right, all right,’ said Larry and Pip together. ‘We’ll take your word for it, Fatty!’