Aiden Moore’s chubby legs couldn’t carry him any faster. His brother Kyle was ahead of him, whooping loudly as he raced along the trail, flattening tiny blades of grass as he tore through the woods, waving the mobile phone.

‘Wait!’ yelled Aiden, but Kyle either didn’t hear or didn’t want to hear.

Grandma Hannah was way behind them now. She struggled with walking fast and had to stop regularly to take a breath from her inhaler. It made a funny, wheezing noise when she used it, like the plastic trumpet Aiden got for Christmas that Kyle had broken. It had been her idea to come on the Gruffalo Spotting Trail on Cannock Chase. Ever since she’d told them about it, Aiden had thought of nothing else. He loved The Gruffalo, and with the app they’d downloaded onto Grandma’s phone, he and Kyle were going to find footprints, spot Gruffalo characters and get their photos taken with them. Kyle knew more about it than him because Kyle had been here before with some school friends.

It seemed he’d been waiting for this day for forever, yet it had only been two weeks since Grandma had visited and told the boys about the treat she had in store for them. Mummy had left her to explain and gone into the kitchen while Grandma had sat with the boys.

‘What happens when you find the footprints?’ Aiden had asked, staring at the mobile phone, his comfort blanket gripped in his small fist.

Grandma smiled. ‘You point the phone at a marker and the character comes to life so it’s in the forest with you.’

‘Will I be able to speak to it?’

Grandma laughed, then coughed and coughed. Eventually she spoke. ‘No, Aidy. They’re cartoon-alive not real-person-alive, but I’ll take your photograph with them and you’ll be able to see them on the app.’

‘They’re alive,’ said Kyle, who’d been watching the television at the time.

Grandma Hannah gave him a look. ‘Not properly alive,’ she said.

‘They are,’ he whined. ‘I’ve seen them.’

Grandma opened her mouth to speak but Kyle suddenly bounced off the sofa and raced off to kick a ball outside. He could never settle to any task for long. He was always twitchy. Mummy had tried to explain he had an attention disorder but Aiden didn’t understand what that meant. Grandma coughed again and turned back to Aiden.

‘You’ll be able to see yourself with the characters.’

‘Owl?’

She nodded. ‘And the others.’

‘And the Gruffalo.’

‘Definitely the Gruffalo.’ She ruffled his hair like she always did when she was about to stand up and leave.

Aiden couldn’t believe it. Mummy had read the story about the Gruffalo to him at bedtime, almost every night for the last month. He would so love to actually see the Gruffalo in the forest. He’d had to wait for Kyle to finish school for half-term before they could go. Mummy hadn’t been keen on their outing because Aiden had had a sniffle for three days and it was a really cold day when Grandma turned up in her old silver Honda to take them to Cannock Chase.

‘I don’t think the forecast is good for today,’ Mummy said. ‘Maybe you should go another day? I don’t want Aiden to get worse.’

Kyle wailed, ‘No! Today. We’re going today. I want to see the Gruffalo.’ He kicked out at the wall in the kitchen. ‘I want to see… the Gruffalo.’ Kyle always kicked walls and doors when he was cross. Mummy pulled him away and tried to explain that they could go another day when the weather was better. Kyle crossed his arms and began crying, loud noises that made Aiden want to stick his fingers in his ears. Kyle could really wail when he wanted to.

‘Stop that now, Kyle. It’s not necessary. You’ve been before. You can go another day when it’s nicer out.’

Aiden’s heart sank into his stomach. He’d been waiting for this day so patiently. He didn’t even feel sick and his nose wasn’t running as badly as it had been and he really wanted to go Gruffalo spotting. Tears brimmed over his thick, dark eyelashes and sobs rose in his throat. He’d thought about nothing else since Grandma said she’d take them to Cannock Chase. It was too much to bear. He’d really wanted to see the Gruffalo.

Mummy glared at Kyle, who shrugged, his tantrum now forgotten. Grandma hugged Aiden and wiped his snotty nose. ‘We’ll go, but we won’t stay for too long. I don’t want you to become ill either. We can go again another day too.’

It took ages for Kyle to get ready. He had lost the trainers he wanted to wear and wouldn’t go until they were found. They got stuck in a huge traffic jam going through Stafford, and then Grandma got lost trying to find the correct car park on Cannock Chase. By the time they arrived at the starting point, it was after lunch and the café was empty of visitors. Kyle decided he wanted some food and Grandma had to buy him a sandwich and crisps. Aiden wasn’t hungry but Grandma insisted he had a sandwich too. She ordered a coffee for herself and seemed to take forever to drink it. Eventually, they got activity bags and were ready to start Gruffalo-spotting. Aiden held his own activity bag tightly in his hand. It contained cards about the animals they might find, including Snake and Owl. He also had a magnifying glass and a special ruler. He didn’t want to lose any of the bag’s contents.

Outside, the temperature had dropped further. The skies had become black and Grandma was worried it would snow. Aiden thought it’d be great if it snowed. Maybe he could build a Gruffalo out of snow. Grandma wasn’t as excited as she had been. Now she looked fed up. She made them wait by the activity centre building and wrapped them up in coats and scarves and woollen hats. Kyle had twisted about and pulled his hat off. ‘I don’t want it. I want to go hunting for characters.’

He’d scampered on ahead, joining a group of three children, and screamed in delight when they found a marker. Grandma had followed with Aiden, who eagerly pulled at her hand.

‘Come on, Grandma,’ he urged.

The other children stood beside a marker point and grinned as their mother took their photograph. Kyle hopped from one foot to the other, eager to take their place. Grandma aimed the phone at the marker and lifted it so Aiden and Kyle could see the short animation. Aiden’s mouth dropped open as he watched a 3D Mouse appear from behind a stump of a tree trunk and run across it. Afterwards, Grandma photographed the pair of them with Mouse. Aiden couldn’t have been happier. Kyle became increasingly impatient and bounded on again. Grandma took out her inhaler.

‘I have to stop for a minute,’ she said.

Kyle came skipping back. ‘Can we go ahead, Grandma? I’ll show Aidy the animals and take the photographs. I know what to do with it. I did it before when I came with James.’

Grandma gave a tired sigh. ‘Go on. You go ahead and look for footprints and markers, but you hold Aiden’s hand while you’re walking and don’t let go of it. Don’t go out of my sight. Understand? You wait for me and make sure you can always see me. I don’t want you getting lost in the woods. Promise?’

‘Yes, yes. Promise. Come on, Aidy. Let’s find the Gruffalo.’

Kyle grabbed Aiden’s mittened hand in his own and tugged him along. At first, Aiden had been able to keep pace with his brother but suddenly Kyle dropped his hand and began walking faster. ‘I’m a hunter,’ he shouted. ‘I’m going to track down the Gruffalo and shoot it,’ he said, pretending he had a gun.

Aiden’s eyes filled with tears. ‘Don’t shoot it.’

Kyle laughed at his misery and began to make whooping noises.

Aiden slowed his pace, his breath now coming out in white, misty clouds. He blew into the air and watched as they drifted away. He wondered if the Gruffalo could make white breath clouds too. Kyle had found a stick and was prodding at the ground with it. Aiden was torn between looking for the footprints and feeling scared Kyle would hurt the Gruffalo. Kyle could be cruel at times. He’d pull legs off spiders and laugh. He didn’t seem to care. Kyle looked across, waved at Grandma who was walking towards them slowly, and shouted, ‘It’s okay, Aidy. I won’t hunt it. I’m only joking. Let’s find a footprint.’

At that moment, Aiden couldn’t find any of the other animals or markers. Kyle had scooted ahead, even though Grandma had told him to stay with his brother. The trouble with Kyle was that he wouldn’t listen. He just did what he wanted to. Grandma had told him off for kicking the back of her seat while she was driving to Cannock Chase. He’d beamed at her and said sorry, but he did it again and again. He wasn’t being naughty. He was just Kyle. He never sat still and he would often become very impatient with his younger brother, who, at five years old, struggled to keep up with seven-year-old Kyle.

‘Come on, Aidy,’ urged his brother, now stooped over something on the ground. He waved the mobile at it and shook his head. ‘No. Not here. Hurry up.’

Aiden trotted quickly to catch up, then remembered his grandmother. He turned to check she was still in sight. She was some way behind. He waved at her and she waved back, her hands beckoning him to return to her, huge sweeping gestures that were unmistakable. Her mouth opened and closed, but he couldn’t catch her words. She waved her hands more agitatedly, but Aiden wasn’t going to return to her. He hadn’t found Snake, Owl, Fox or the Gruffalo yet. He scampered in the direction his brother had taken. The path twisted and turned between trees and suddenly Aiden came across a clear footprint. It was huge. How could Kyle have missed it? It must belong to the Gruffalo. He concentrated on looking for more prints and a marker point. The Gruffalo would be there. He found another large footprint and spun around, desperate to find Kyle and the mobile phone that would allow them to bring the creature to life. His brother had disappeared and Aiden had wandered further into the woods than he intended. He couldn’t spot the trail they’d been on. He turned and tried to retrace his steps but ended up completely lost. Black clouds that scurried across the sky suddenly turned day in the direction of night.

‘Kyle,’ he called. There was no reply. He brushed through the undergrowth and startled a bird that chattered angrily at him, making him jump. ‘Kyle,’ he said again, this time more uncertain of himself. The woods didn’t seem to be quite as friendly.

He began to shake with cold and anxiety. There were no markers here – the big arrows he’d been told to follow. Then he remembered the Gruffalo was friendly and would help him find his way out of the woods. He just had to find it.

He stumbled on in the gloom, nudging past some tall ferns and a few trees. All the while, he clutched his activity bag to his chest. He could hear rustling ahead and then… he saw feet – feet and legs. The Gruffalo was hiding under a bush, near a clearing.

‘Hello,’ he whispered. The Gruffalo didn’t answer or move. Aiden wondered if maybe he was angry for some reason, or playing hide-and-seek. The wind moaned quietly through the trees, frightening Aiden, now suddenly anxious that the Gruffalo would leap out and try to scare him. Kyle sometimes did that and Aiden hated it. He wanted to go home. He backed away from the bush and further into the clearing, and when he turned, there in front of him was a car – a red car exactly like Mummy’s. Mummy had come to find him. He trotted up to it and stood on tiptoe to let Mummy see him. He wondered if Kyle was already inside.

He tapped on the window and pressed his face against it. For a moment his mind couldn’t process what he was seeing. This wasn’t Mummy’s car. It belonged to a man – a man with his swollen tongue hanging from his mouth, and red-veined eyes wide open, staring at Aiden. The activity bag tumbled to the ground; cards, ruler and magnifying glass spilled out. Aiden let out a terrible wail and began to call desperately for his grandmother.