Archie had arranged to meet up for lunch with Fliss and Billy at Clootie Dumpling’s after his visit to the dentist. The cosy café was hidden at the back of the McBudge Fudge Shop next to the factory, and its nooks and crannies were always filled with delicious smells. Miss Dumpling (who everyone thought might be a witch because of her sparkly eyes and her habit of knowing just what you wanted to eat) made hot chocolate that was famous throughout Dundoodle for its sweet, dark richness, and the children often used the café as a place to chat and relax after school.

‘Why have the Puddingham-Pyes asked you to their birthday party?’ said Fliss, after Archie told them about his encounter with Garstigan. ‘I thought they hated you.’

‘They don’t have anyone else to invite,’ said Billy. ‘It’s not like they have any friends.’

‘Maybe they’re trying to be nice,’ said Archie. There was silence for a second before they all burst out laughing at the idea. ‘Speaking of nice …’ Archie told them about Edward Preen and the dentist’s threat against the McBudge Factory.

‘He sounds like a total crackpot to me,’ said Billy, dismissively slurping his hot chocolate. ‘Who would want to give up sweets?’

‘He’s already started with his campaign,’ Fliss said. She went over to the counter and picked up a piece of paper from a pile by the till. ‘I saw these when I came in,’ she said, showing the leaflet to Archie. Printed on it was a very flattering picture of Mr Preen’s smiling face, beneath a banner with Normal, Inoffensive, Cleansing and Educational written on it in huge letters. Under the dentist’s handsome chin were the words:

Stop the rot! Put an end to the unnatural pollutant of sweetness.

Join the N.I.C.E. campaign to promote dental and mental hygiene: clean your teeth and your mind!

BE N.I.C.E. AND BANISH NAUGHTINESS

(COMING SOON: New, healthy treats for all the family.)

‘Healthy treats?’ scoffed Billy. ‘They don’t sound very nice at all.’

‘Relax,’ said Fliss. ‘It sounds harmless enough to me.’

‘I can’t believe he had the cheek to leave these in here!’ said Archie, screwing up the leaflet indignantly. ‘I’ll get Clootie to throw them in the bin.’

Just then, Clootie came to their table with a large plate of biscuits. She was very embarrassed when Archie showed her the leaflet.

‘So sorry, Mr McBudge!’ she said, flustered. ‘He was such a charming man, I didn’t realise he was up to no good. I don’t know what I was thinking! I’ll remove them at once.’ She placed the plate on the table. ‘Have a Gingerbread Dragon to make up for it – they’re fresh from the oven.’

‘Ooh, I’d forgotten it was that time of year,’ said Fliss, grabbing one of the dragon-shaped biscuits.

‘What time of year is it?’ said Archie.

Billy and Fliss stared at him.

‘You mean you don’t know about …’ said Billy.

‘You mean you’ve never heard of …’ began Fliss.

‘Don’t know about what?’ said Archie, between mouthfuls of dragon. It was very tasty: rich and spicy with a soft but dense texture. ‘Never heard of what?’

‘Unquiet Night,’ Billy and Fliss said together. A shiver ran down Archie’s back at the words.

‘What’s that?’

‘Unquiet Night is when the dead and undead walk, and the spirits and ghouls rise,’ said Billy. ‘Legends say the magical folk come out of hiding for the night and dance the Dance of the Wyrd.’

Archie frowned. ‘That sounds like Halloween to me,’ he said.

‘It’s nothing like Halloween!’ said Billy hotly. ‘What a ridiculous idea!’

‘Dundoodle doesn’t have Halloween,’ explained Fliss. ‘Halloween is at the end of October, and in Dundoodle that means icy wind and horizontal rain. The weather’s so miserable even the undead stay in and watch TV! So we have Unquiet Night in the summer instead. It’s always on the first Tuesday after school finishes – just over a week away. The town holds a festival for it, with special home-made food – spiced fruit punch, toffee apples …’

‘Coffin Cake!’ said Billy.

‘Witchberry Buns!’ said Fliss.

‘Spellcaster Sugarbeer!’ laughed Billy.

‘And Gingerbread Dragons,’ said Fliss. ‘People dress up in costumes and go around the town knocking on people’s doors to get sweets.’

‘You mean trick-or-treat?’ said Archie.

‘It’s called the Wyrdie Walk here. Then there’s music and dancing by lantern-light, all kinds of games, and a brilliant, creepy puppet show. It’s loads of fun!’

Archie grinned. Trust Dundoodle to have its own special, spooky holiday!

‘It’s not fun at all,’ said Billy huffily. ‘It’s a crucial time of study for a wyrdiologist. At least one of us is taking their responsibilities seriously.’ He gave Archie a meaningful stare.

Archie sighed and told them about the second meeting with the strange little man, showing them the orange leaf he’d been given.

‘I might be trying to ignore the Wyrdie Tree, but it’s not ignoring me,’ he said.

‘What does it mean?’ asked Fliss. ‘What are these signals?’

‘They are messages from the Tree itself,’ said a voice with an accent Archie recognised. The little man was stood next to their table.

‘It’s you!’ said Fliss. ‘You were on the moor.’

‘That was my brother,’ said the man.

‘And I saw you outside the dentist’s,’ said Archie.

‘That was my other brother,’ said the man, sounding a bit embarrassed. ‘We’ve all been searching for you, Guardian. I have brought you this.’

From inside his cloak he produced a small, black, sleepy animal. Its velvety nose sniffed the air.

‘That’s a mole,’ said Fliss.

‘Sorry,’ said the man, hurriedly putting the creature back in his cloak. ‘That’s Ingeborg. She likes to snooze in my pocket.’

He then presented Archie with a third leaf. This one was red.

‘The final signal,’ he explained. ‘The Tree has summoned you, Guardian. And this time, you must heed its call.’

‘I haven’t had the chance, the other times,’ said Archie. ‘You keep disappearing.’

The man blinked in surprise. ‘We thought you’d know what to do,’ he said. ‘But then we’ve never had a Guardian so young … You’re supposed to reply, “the Guardian accepts the summons”.’

‘There’s no manual for this job,’ said Archie in frustration. ‘What does the Tree want?’

‘We cannot talk here,’ said the man, lowering his voice. His eyes darted about the room. ‘The Mirk could be hiding anywhere! Meet us at the Tree tomorrow. We will be waiting.’

‘Hold on a minute!’ said Archie. ‘Why can’t we talk here? What’s the Mirk?’ But the man had already slipped away into the crowd of customers and was gone, leaving only the smell of warm earth behind.

‘It looks like we are going to visit the Wyrdie Tree, after all,’ said Fliss smugly. ‘We’re having an adventure whether you like it or not, Archie McBudge.’

‘There’s only one problem with that,’ said Archie, helping himself to another Gingerbread Dragon. ‘We don’t actually know where the Wyrdie Tree is …’