The ghost-girl held her hands up.

‘I’m sorry, I didn’t mean to frighten you,’ she said. ‘I won’t harm you, I promise. I only wanted to talk. It’s been a long time since I’ve had a chance to talk to anyone … anyone like you.’

Cat looked into the ghost-girl’s wide, frightened eyes and believed she was telling the truth.

‘I’m sorry about your friend,’ said the girl. ‘I really am. I didn’t want to help lure him here, but she made me.’

‘What was that thing?’ asked Cat. ‘And what has she done with Shane?’

‘Shane,’ said the ghost-girl. Her face took on a dreamlike quality and she seemed to stare right through Cat. ‘That name’s familiar. I think maybe I had a brother called Shane once … it’s been so long, I don’t remember.’

‘I don’t have time for this,’ snapped Cat, wondering if it would even be possible to grab the spectre and shake her. ‘My friend’s just been dragged below the water, and I don’t know how long he can hold his breath.’ How long had he been under there, she wondered. Thirty seconds? A minute? She couldn’t even remember if Shane could swim or not.

‘Sorry,’ said the ghost-girl meekly. ‘The creature who took your friend is a Merrow, a kind of water spirit. She lives in the lake and lures children here with her song. She keeps us here as company for her until …’ the ghost-girl trailed off.

‘Until you die.’ Cat finished.

She nodded and her translucent head seemed to flicker in and out of existence. ‘Her magic keeps us alive, for a time – hours or even days sometimes – but we all die in the end.’

Cat was horrified. ‘How … how many children does she have down there?’ she asked.

‘Oh, I lost count years ago,’ said the ghost-girl. She spread out her hand and from below the water dozens of pale figures emerged. Some, like the girl before her, were dressed in old-fashioned clothes and were so translucent they were almost invisible. Others were much more solid looking. They had one thing in common though: none of them seemed older than twelve or thirteen.

‘And you’re trapped here?’ Cat asked, almost afraid to learn the answer.

‘Yes,’ the ghost-girl said, and the weight of sadness in her voice almost broke Cat’s heart. ‘As long as she’s stuck here, so are we.’

Cat’s stomach dropped like a stone. She couldn’t let that happen to Shane. She couldn’t leave him here with the Merrow.

Think, Cat!

The Clurichaun had warned them about the Dullahan and told them how to get away from him. He must have done the same with the Merrow too.

She took a deep breath and began to recite the song again.

‘A lonely voice leads travellers astray, her watery kingdom is where they’ll stay,’ – that part made sense, but the next few lines stumped her.

‘As rivers into sea must flow, so too must this maiden go. And all souls shall be free to roam once the maiden has gone home.’