‘Next we cross the Raging River at the Safe Hands Bridge,’ she said.

‘I can’t see any sign for the Raging River,’ said Shimlara.

‘Neither can I,’ said Nicola. ‘I guess we’ll just have to head west. So that would be, um . . .’ She looked up helplessly at the rainbows arching over them. Which way was west? She had absolutely no idea.

‘We need a compass,’ said Tyler.

‘Ahem,’ said Greta. They all turned to look at her. She was holding her compass up high. ‘Luckily some of us packed something useful.’

‘Oh, well done,’ said Nicola, wishing she’d been the one to bring a compass.

‘Don’t worry, Nic,’ said Sean. ‘I’m sure your jar of turmeric will come in useful soon.’

Nicola made a face at him.

Greta studied the compass for ages with a deadly serious expression on her face, until Sean said, ‘Are you sure you know what you’re doing?’

‘Of course I do,’ snapped Greta. ‘Unlike Nicola, I have brilliant navigational skills.’ She looked up from the compass and pointed to her left. ‘That way.’

‘Good,’ said Nicola. She looked at her watch. ‘We’ll try and go a bit faster. We don’t want to be crossing the river in the dark.’

Nicola saw Sean give her a grin of understanding.

‘Will you be all right going a bit faster, Greta?’ Nicola asked innocently.

‘I’ll be fine,’ said Greta grimly.

Nicola tapped her feather hard and Quicksilver responded by breaking into such a fast gallop Nicola was sure she would fall. That would make Greta completely unbearable.

After a few seconds she managed to get her rhythm back and start to enjoy the sensation of pelting across a snowy field, the air rushing against her face. They passed another marshmallow mine, a village and a ramshackle old school.

A few minutes later, she saw a sign saying RAGING RIVER, with an arrow pointing straight ahead. They pounded along, going up a small hill, and Nicola caught a glimpse of a frozen sea in the distance before they plunged down again, following a winding track in and out of huge grey tree trunks that soared as high as the arches of the rainbows.

There was a sound of rushing water.

‘Whoa!’ She pulled on Quicksilver’s reins. ‘I think we’re here.’

Nicola looked with fascination at the river in front of her. She’d never seen such angry, powerful water. It frothed and boiled and bubbled like water bursting from a fireman’s hose. There was no way you could swim in it – it would toss you about and tear you to pieces.

The river was so wide Nicola couldn’t see the other shore. She looked around for the Safe Hands Bridge. There it was – a thin, rickety bridge that seemed to be held up by string.