‘How?’ Liska asked. ‘Who is this person you know? And why don’t they just go and tell the treekeepers themselves?’

Lug fell silent again. His cheeks flushed and he shot Liska a guilty look. Then he gave a guilty glance over her shoulder.

Liska followed his gaze and saw he was looking at a patch of scruffy woodland in the distance. Separated from the circles of the forest, it was sandwiched in between the mountains and the swampy Scrubbings.

‘The Cryptwood?’ Liska had flown over the deserted patch of trees before. She had seen the dead branches with their iron-grey bark. She had heard the owls hooting between its misty, cold trunks and had listened to the spooky stories about what lived within. All the time she had thought it was just creepy nonsense to scare tiny children with.

‘I did something I’m not supposed to,’ said Lug, his eyes fixed on the ground. ‘I heard something I probably shouldn’t.’

Liska was about to press him for more when she heard a familiar noise. One which usually spelled danger, even death.

Crrrrrrrrackkkkk!

‘Rockslide!’ she shouted, leaping up to grab Lug and shield him. Only after she had wrapped her arms around him did she realise they weren’t three hundred feet up, balancing on the sheer mountain face, so they were probably quite safe.

In the distance, a cascade of small boulders tumbled and smacked their way down the mountainside, breaking into fragments before splashing into the swamp with muddy, sticky explosions. Splap! Splap! Splurp!

By instinct, Liska followed their trail with her eyes to see if any more were coming. That was when she spotted the figure standing on a ledge fifty metres up, at the bottom of a jagged split in the granite.

‘There’s somebody up there,’ she said, releasing Lug who jumped away as far as he could, still squirming.

‘Where?’ he said, peering up at the rock.

‘On that ledge,’ said Liska, pointing. ‘Someone in black robes. And he’s doing something . . . magical.’

The figure was gesturing, moving in the way Liska had seen mages do when they summoned up their power. It looked as though he was trying to open up the granite mountain behind him, as though he was forming some kind of a gateway.

Lug, squinting upwards, had seen him now. Suddenly his face went even paler than usual. ‘Is that . . . could it be . . .’

‘The arbomancer! The father of that bully from the playground!’

‘Yes, Noxis. But what is he doing?’

The pair watched as the mage finished his spell. Then he stood aside and waited. Waited for something to come through the tunnel he had made.

Liska and Lug moved closer and clutched each other again. They stood with their necks craned upwards, breath held, staring at the spot where the thing would emerge.

Both of them had an idea what it might be, but the actual sight of it made them step backwards in terror.