They skim the treetops and, as the forest falls behind, Polly spies the jagged blue mountain range that is the furthermost point of Blackmoon Coven. An eerie purple mist hovers above it. As they draw closer, Polly smells a terrible smell of damp and jackrock and sorrow.

She stares at the mountain ahead of them. A dark red gash splits open one side. Even though the sight of it chills her, and Miss Spinnaker’s warnings still ring in her ears, she knows this is where she is meant to be. This is where the stones have been leading her ever since Miss Spinnaker activated them in her little kitchen a lifetime ago. That was the moment everything changed.

Whatever those stones want me to do here, Polly thinks, I am not going to let them down. I will prove to Miss Spinnaker that I am not just an ordinary nine-year-old witch, bad at spells and even worse at holding my temper. I am a Silver Witch!

‘Come and get me!’ she yells out over her shoulder, to where she imagines Mrs Halloway will soon be closing in on them. Then she tips the front of the broom gently downwards and they begin their descent.

‘What is this place?’ Buster asks, peering over her shoulder, his voice full of fear.

‘The Hollow Valley Mines,’ Polly says quietly. She already knows that Buster will be horrified.

‘The Hollow Valley Mines?’ he repeats. ‘But those mines are haunted, Polly! Everyone knows that! Nobody goes into the Hollow Valley Mines anymore!’

‘Well then, we can be pretty sure this is a safe place to hide from Mrs Halloway, can’t we?’ she says, sounding braver than she feels.

After all, what witch or monster isn’t scared of ghosts?

Silently, Polly drifts to the ground. They land on the rocky slope with a gentle thud. Polly hides Miss Spinnaker’s broomstick behind a rock and the two of them stand for a moment, staring into the dark gaping hole in front of them.

Polly takes a deep breath. Mrs Halloway will be only moments away and they have no time to lose. She takes Buster’s paw and they walk slowly towards the opening of the mines.

Polly knows she would have never really been brave enough to do this on her own. And, not for the first time, she feels thankful for the warmth of Buster’s paw in her hand.