At breakfast the next morning, Mum was in a bad mood. Oranges were mercilessly pulverised into juice, toast was buttered into submission, and tea was slurped with extreme prejudice.

‘Anything … the matter, madam?’ enquired Tablet, arming himself with a spatula, just in case Mum decided to use the sausages as missiles.

Archie thought he already knew what the problem was.

‘Is it Mr Preen again?’ he asked.

Mum slammed her knife down on her plate, the sudden clatter sending Sherbet diving for cover under Archie’s chair.

‘That man is a nightmare!’ she said. ‘The committee to organise the Unquiet Night Festival events is practically falling apart!’

‘Why? We’ve only got a couple of days to go.’

‘I’m beginning to think there won’t be an Unquiet Night Festival at all,’ said Mum. ‘When Preen first showed up, a few people agreed with him. Now, half the committee have resigned because they think Unquiet Night is unwholesome. And, even worse, the N.I.C.E. campaign is threatening to protest outside the factory! I thought there’d be more resistance, but it feels like half of Dundoodle is sleepwalking its way around to Edward Preen’s way of thinking.’

Preen’s evil influence was spreading like a disease.

After breakfast, Billy and Fliss arrived. It was a rainy Sunday, but that didn’t dampen their excitement. There was lots to talk about, so they hurried to the hideout. Billy and Fliss were flabbergasted when Archie told them what had happened at the party.

‘You were lucky to get out of there alive!’ said Billy, on hearing of Portia and her flamethrower. ‘I wouldn’t have wanted to be you, caught between the P-Ps and Preen and the cake apocalypse.’

‘Preen is some kind of … evil spirit?’ said Fliss. ‘I can’t believe it! He’s a dentist. He gave Gordon McPlankton two fillings and a scale and polish. That’s not exactly the kind of thing the Prince of Darkness would do.’

‘That’s why it’s the perfect disguise,’ argued Billy. ‘He’s respectable – whoever heard of a demon dentist?’

Archie nodded. It all made sense … or did it? A small doubt lurked annoyingly in his mind. Was it some wyrdworking instinct he had? He dismissed it.

‘If we didn’t already have a reason to avoid Preen,’ he said, ‘we’ve got one now. Keep away from him! We don’t know what he might do.’

Meanwhile, Billy had been reading through Belle’s journal.

‘It’s hard to understand some bits because of the old-fashioned way of writing,’ he said. ‘She talks a lot about her honey-dragon friend. She called him Corignis. She also mentions the Fjurge Brownies. I think she thought they were rather funny.’

‘Does she say anything about the Mirk?’ asked Fliss impatiently. ‘Or about the Treeheart?’

‘No. The entries stop a few days before Unquiet Night. There are just a few empty pages at the end.’

‘Why did she give her journal to the dragons to keep?’ said Archie. ‘It doesn’t make sense, if there’s nothing useful in there, nothing to tell us what she did with the Treeheart.’

‘Maybe she’s still got it,’ said Fliss. ‘Maybe they buried it with her in the graveyard.’

‘Belle McBudge is buried in Dundoodle?’ asked Archie.

‘Of course she is. In the McBudge family vault. All the McBudges are buried there, Archie. Maybe we should pay her a visit.’

Archie raised an eyebrow. ‘Maybe we should…’ he said. Billy’s eyes almost popped out of his head.

‘Are you seriously saying you want to go and dig up Great-Great-Great-Times-A-Hundred-Auntie Belle McBudge from her maggot-ridden grave and see if she’s clutching the Treeheart in her cold, dead, skeletal hands?’ he asked, in disbelief. ‘That’s awesome!’

‘I’m not saying we should dig her up,’ said Archie. ‘At least, not yet. But hiding the Treeheart in a grave sounds plausible and, let’s face it, we’ve not got much else right now.’

As they passed the factory entrance on their way to the church, the children were surprised to see a small crowd of people loitering by its gates – it was Sunday, and the factory was closed.

‘They’re N.I.C.E. protestors!’ said Archie. ‘Mum said Preen was threatening to do this.’

The protestors were handing out Preen’s Safer Wafers to passers-by and carrying placards with slogans like

Sugar + Spice Is Not N.I.C.E.!

Chuck Out Chocolate and Stamp Out Sweets!

and

McBudge Fudge is Sludge!

which Archie found particularly offensive, after all the trouble he had gone to finding its secret ingredient last winter.

‘There are only a few of them,’ said Billy lightly. ‘It could be worse.’ Archie gritted his teeth and kept his head down as they passed the huddle of people. He had a feeling things were going to get a lot worse before they got better.

The three friends quickly made the journey across a rain-soaked town. Lurking in the shadow of the stunted spire of Saint Bawgbreath’s Church, the graveyard was surrounded by a wall whose cold, white flints had a look of ancient, lumpy bones. Grass and wildflowers grew high around the graves and there were occasional cackling barks from a family of foxes hidden in the undergrowth. Billy, a regular visitor, led the way.

‘This place is absolutely stuffed full of corpses,’ he said with relish, guiding them on a path between the lichen-covered headstones, ‘so no one new gets buried here any more. But the McBudge’s still have a bit of space in their vault if you were thinking of planning ahead, Archie.’

Archie shivered.

‘I am not,’ he said firmly.

At the back of the yard, overhung by a large yew tree, stood the McBudge vault. It was like a miniature temple, all stone columns and depressed cherubs. The McBudge coat of arms was inscribed on its metal door.

‘It’s very small,’ commented Fliss. ‘How can all your ancestors fit in there?’

‘This is just the entrance,’ said Billy. ‘The vault is underground.’

Archie pulled on the metal door handle. The lock was ancient and decayed, and crumbled away before his eyes. It took all three of them to open the door, its rusty edges scraping against the stone as it slowly swung open. Steps led down into darkness. The dead awaited them.