‘Maybe. We should have sunk it,’ the Crow muttered. ‘Why didn’t you think of that!’ He turned to face the front, and stared.

Ahead of them was no stream now but a full-sized river, and they were being swept along faster than they could row.

Suddenly the roar of the water was noisier.

Tomos called out something that sounded like, ‘Rooks!’

‘No time for birdwatching,’ the Crow said.

Tomos yelled again, and pointed. ‘There!’

Seren peered closer. ‘Not rooks,’ she murmured. ‘I think he means…’

‘ROCKS!’ Tomos screamed.

The boat slewed. Seren gave a cry. Everything was wrong; they were bumping up and down, flung sideways. She dropped her oar and it fell into the water; she grabbed over the side for it but it was already gone.

Tomos pulled her back.

The Crow was hunched down, wet and miserable. ‘Lord, how I hate adventures,’ he muttered.

Now the boat was quite out of control. They had to hold on tight as it whirled and sped past high banks hollowed with holes, under trees, out into deeper currents.

‘What can we do?’ Seren yelled.

‘Where’s the Egg?’ Tomos rummaged for it.

‘No! Don’t get it out! We’ll lose it. And…’ She stopped. Suddenly she could hear a deep, thundering roar. It came from ahead, round a bend in the river, and it was getting louder all the time. ‘Oh no,’ she whispered.

The boat almost tipped over. It rounded the bend and the noise redoubled.

‘It’s a waterfall!’ Tomos yelled. He looked at her. ‘Seren. Can you swim?’

‘Not a stroke’, she whispered.

‘Neither can I,’ the Crow wailed.

The roar of the water was terrible. As the boat swirled closer to the falls they were deafened with it. Seren could barely hear what Tomos was shouting.

‘Jump! I’ll … you … safe…’

‘No!’ she yelled. ‘I can’t!’

She had never been so scared. And she was soaked, her hair plastered to her face.

The Crow was huddled in the bottom of the boat. ‘Fly away,’ she yelled at it. ‘Before we go over!’

The falls must be very close but there was nothing to see but spray and rainbows. The Crow took no notice of her. It was muttering something. It had its head in Tomos’s bag; it was talking but she couldn’t hear a word it was saying.

Then it re-emerged, dragging something round and silvery.

The mirror?

It was too heavy. The Crow dropped it, hopped up and yelled in her ear.

‘Throw it overboard!’

What?’

‘THROW IT OVERBOARD!’

For a second she just stared. Then, taking a breath, she knelt up in the swirling boat, picked up the mirror and threw it. It went flashing through the air, and landed with a great splash between two sharp rocks.

It sank at once.

‘What use was that?’ Tomos yelled.

Seren shook her head.

But wait!

Something was happening. Where the mirror had slashed into the water, a circle of ripples was beginning. It grew smoother and wider. She saw that the whole river was slowing and growing and changing, that it was transforming even as she watched, all the rocks submerging, all the splash and bubble smoothing out.