‘… but the brave girl wasn’t really alone. She had her wits and a faithful companion by her side.’

A sudden gust of wind rattled the window and Cat looked up. For a second, she thought she caught a glimpse of a too-wide face pressed up against the windowpane, grinning down at her through the gap in the curtains. She began to panic. None of this was right!

‘Caitriona,’ said Granny, placing a warm hand on her knee. Her voice was muffled, as though it was coming from under-water. ‘You’re going to wake up now. You need to save Mikey.’

Her vision began to fade in and out like a badly tuned television.

‘Do you hear me, child? Save Mikey. You’re his only hope.’

Cat tried to hold on, tried to focus on the words Granny was saying, but the wind and the laughter were addling her mind and she couldn’t concentrate.

She tried again to speak, to ask what was going on, but it was too late. The scene before her went black and Granny was gone.

The bulb in the desk lamp burnt out with a loud pop and Cat jerked awake. It took a few seconds for her eyes to adjust to the dimness and for her hammering heart to calm down. It was OK, she was home. She looked around her bedroom, at her bed and her bookshelf and her battered old teddy bear collection. Everything was as it should be. She checked the time and found it was only half six. Far too early to be up yet. Cat pushed herself up from the desk, body stiff from sleeping in such an awkward position all night. No wonder she had such a strange dream, she thought. Then she paused. What had she been dreaming about? She tried to recall, but the details were already slipping away from her like sand through her fingers. No matter, her bed was calling.

Cat slid the Book of Secrets back into its hiding place and staggered across the room. She had just settled back underneath her warm duvet when she remembered.

‘You have to save Mikey.’

Before Cat had time to think twice about what she was doing, she leapt out of bed and hurried into the hallway. Carefully, she eased open the door of her baby brother’s room.

Mikey’s room was almost totally dark save for the faint glow of the nightlight plugged into the wall. Straining her eyes, she could just about make out the outline of the cot silhouetted against the curtain and a small, lumpy shape lying inside. Mikey wasn’t moving or making the snuffly snoring noises that usually let Cat know he was asleep. Worry sat in the pit of her stomach like a stone, but for the life of her she couldn’t have said why.

‘Mikey? Are you awake?’ she said, taking a tentative step into the room. The floorboards creaked beneath her feet and the lump in the cot began to squirm.