His claws scraped against the edge of the third circle. He gritted his razor-sharp teeth and stretched further, until his fingertips found purchase on the edge of the floor.

Zac felt the muscles on the Angelo-demon's back contract, even as he felt the first stirrings of panic fluttering in his own stomach. He looked at Angelo's horns. They were several centimetres shorter than they had been just a few seconds ago. His neck and shoulders now seemed significantly less broad too, and his hard scales felt considerably softer.

"You're shrinking! Why are you shrinking?" Zac groaned. "Not now. Don't change back now!"

"S-sorry," Angelo groaned. He was looking more and more like his old self with each moment that passed a" an enormous version, granted, but his old self all the same.

His skin was going from red to a flushed pink. His horns had all but retreated into his skull. When he reached for the next floor, his arm fell a metre short. He was barely twice the size of Zac now, and he was shrinking fast.

Demons swarmed along the floors above and below them, fighting each other to be the one who stopped the escape.

Zac searched desperately for a way out, for a way past the squawking, chittering hordes, but there was no time to plan, no time for anything as Angelo returned to normal size. Clinging to each other, they fell. Down through the circles of Hell. Down past the braying demons. Down towards the broken floor and the shadowy embrace of the tenth circle beyond.

A sound, like a ripple of applause, filled the air around them. Hands caught Zac firmly beneath the arms and their descent began to slow. He tightened his grip round Angelo and looked up. A pair of feathery white wings filled his field of view.

An angel, he thought, until he saw the bloody wound on one of the wings and instead thought: a Valkyrie.

"Stop squirming," Herya hissed, her face contorted in pain as she beat both wings as hard as she could.

"I wasn't squirming."

"Well, stop talking then!" she spat.

"Is that Herya?" Angelo asked.

"Yeah."

"Hooray! Hello, Herya! You came back for us!"

The Valkyrie hissed again. "Regretting it already."

Zac felt his toes brush against the carpet. He caught a glimpse of Haures's fiery eyes blazing in the darkness of the tenth circle, and then they were rising again, climbing, soaring up towards the upper floors of Hell.

As they passed the third floor, a chubby demon with a Mohican haircut took aim with something that looked worryingly like a bazooka. A door flew open behind him and another demon in red pyjamas emerged. The new arrival raised a particularly heavy hardback copy of Jekyll & Hyde above his head, then brought it smashing down on the back of the other demon's Mohican.

The demon stumbled forward and crashed through the frosted-glass barrier. His eyes went wide. "Ooh, bugger," he mumbled, and then he and the bazooka went down as Herya and her cargo went up.

"Go on, son!" cheered Murmur, punching the air in triumph.

"Thanks, Dad!" Angelo shouted back. He waved enthusiastically as they passed the third circle and carried on all the way up to the first.

A squadron of uniformed demons were ready and waiting for them. "Halt!" commanded the leader. "In the name of the Dark Lord, Satan, I command you toa""

He stopped talking as Herya's forehead met his nose. The rest of his platoon stood gaping in surprise. Many of them had dreamed of the day their commanding officer would be cut down to size, but now it had come they weren't quite sure how they felt about it.

Zac didn't hesitate. He cut through them, all fists and feet and elbows and knees. Herya mopped up what was left, and in moments the three of them were surrounded by little mounds of unconscious monsters.

Angelo gave a low whistle, then smiled. "Crumbs. That was exciting, wasn't it?"

Zac looked the skinny boy up and down. "What I want to know," he said, "is how have you still managed to keep those trousers on?"

Herya was staring down at the senseless demons. She drew in a deep breath. "A fight. My gods. I was in a real fight."

Zac laid a hand on her shoulder. "You OK?"

"Are you kidding? That was brilliant!" she giggled. "Let's find more of them and do it again."

"Let's not," suggested Zac.

"Cretins," crackled the voice of the Dark Lord. "Stop them! Stop them now! Do not let them get to the main door. Do not let them escape!"

"Main door's this way," said Zac, leading them towards the exit he knew led to the reception area. He yanked it open and they tumbled inside. "Now, out here and we're home and dry."

A small figure in a large suit sat on the other side of the reception desk, his hands behind his head, his feet resting on the table. He gave a vague wave of his hand and the double doors that led out of Hell melted away and were replaced with solid rock.

"Surprise," said Satan. There was a sound like inrushing air, and Haures appeared in the doorway behind them. The Dark Lord leaned in towards the intercom again. "Oh, don't let them get to the main doors," he said in a falsetto voice. "Whatever will we do if they reach the main doors?"

Zac heard Angelo gasp. "This was a trap," the half-angel whispered.

"You think?"

"Who are you?" demanded Herya, eyeballing the Dark Lord.

Zac did the introductions. "Herya, Satan. Satan, Herya."

Herya dialled the eyeballing back a few notches. "Oh," she said, then said nothing more.

"And the gentleman behind you is Haures," Satan said. "He's one of the Dukes ofa""

"Hazzard," said Zac and Angelo together, then they exchanged a quick high five.

The Dark Lord swung his feet down and emerged from behind the desk. "Very amusing," he said. He regarded Zac. "So you came back for your colleague."

"No," said Zac. "I came back for my friend."

"Ker-ching!" cheered Angelo. "Back of the net!" He tried to hug Zac, but was nudged away.

"Not now," Zac told him.

Grinning broadly, Angelo began body-popping. "He likes me. He likes me. He really, really likes me," he sang in a robotic voice.

The demons watched him in bemused silence. After several seconds, Angelo stopped dancing. He coughed quietly. "Carry on."

Satan hesitated. "Right..." he said a little uncertainly. "Angelo will be taken back down and restored to his true form, while you two are given to some of my more... creative staff to have fun with." He smiled thinly. "Fun for them, you understand? Not for you."

The Dark Lord returned to the Tannoy and began calling for reinforcements. Zac, Angelo and Herya stood back to back, allowing them to keep an eye on both demons at once.

"What do we do?" whispered the Valkyrie.

Zac's mind raced. "I... I don't know."

"Why did I come back for you?" Herya groaned. "I could've been in Vegas by now."

"Shut up and let me think."

"I've got an idea," Angelo said, "but you won't like it."

"Right now, I'm prepared to try almost anything," Zac replied. Satan looked up from the Tannoy microphone, a vague expression of amusement on his face. From out in the corridor, Zac could hear the sound of hurried footsteps approaching. "What's the idea?"

Angelo took a deep breath. "We pray."

"Pray? That's your idea? We pray?"

"Have you got a better one?"

"I told you, I'm not praying," Zac said.

Satan took a step closer. "What are you whispering about, little ones?" he asked them, and his forked tongue flicked across his lips.

"Come on, what harm can it do?" Angelo asked.

"Whatever you're planning, just do it," Herya urged. She had her fists raised, but it was clear from the way her shoulders sagged that she didn't fancy their chances.

"You said you'd try anything," Angelo reminded him.

"I said almost anything."

"Just do something!" Herya yelped.

"Oh, all right," Zac snapped. He pressed his hands together. "Dear God, please save us," he said. He turned to Angelo. "Happy now?"

"You didn't say Amen."

Zac sighed. "Oh, well I'm sorry," he said. "Amen."

And as the word left his lips, the air was filled with blinding light and a joyous chorus of Hallelujahs.

Zac rubbed his eyes.

Angelo and Herya and Satan and Haures all rubbed their eyes too. As did the little old man who was suddenly just there, sitting in his favourite armchair in the corner of his living room.

Zac looked around at the familiar wallpaper, the familiar carpet, the familiar everything. He looked at his grandfather, who was staring open-mouthed at the five figures who had suddenly appeared in his front room out of the blue.

"Granddad?" Zac muttered. Phillip turned towards him and an expression of relief crossed the old man's face.

"Oh, Zac, there you are," he said. His fingers squashed his globe-patterned stress ball over and over. "I heard you, Zac. In my head. I heard you calling for help. Please save us, that's what you said. I heard you."

Zac frowned. "What? I mean... you did?"

"Hey, look. It's like the song," chirped Angelo. He nudged Zac in the ribs and pointed at Phillip's stress ball. "Your granddad. He's got the whole world in his hands!"

Zac stared at the globe. Then he stared at the old man's brilliant blue eyes. All those voices his granddad had heard for all those years. Asking him for help.

No, not asking.

Praying for help.

He had heard their prayers, and as far as Zac had ever been told, there was only one being who could hear people's prayers. One supreme being.

"Oh," said Zac. He swallowed. "My God."

HE DARK LORD Satan, Father of All Lies, cleared his throat politely.

"Would someone care to tell me what's going on?"

Philip turned to look at Satan. A flicker of recognition crossed his face, and just then, just for a moment, it wasn't Zac's granddad sitting in the chair. It was someone older. Much older. As old, in fact, as time itself.

The air around him crackled in a blaze of light so blinding that Zac was forced to shield his eyes. Phillip spoke, and when he did, his voice seemed to roll in from every direction at once.

"You," he said, and the whole world shook with the power of it. "Don't I know you?"

Satan licked his lips, which had suddenly become very dry. "What, me?" he said, brushing his fingers through his hair and hiding the stumps of his horns. "Um... nope. Don't think so."

"Oh."

The light stuttered and faded, and Phillip became his old self again. Zac glanced at the others. Only himself and Satan seemed to have noticed the change that had come over his grandfather.

He quit. That's what Angelo had said. Almost one hundred years ago, he'd quit. And nobody knew where he went.

Phillip gazed across the group. "Zac, who are these people?" he asked. "Why's that one got wings? And why's he in fancy dress?"

"Fancy dress?" growled Haures. He lunged at Phillip. "I'll show you fancy dress, you olda""

As his hand touched the old man, the demon popped like a bubble and disappeared. Silence fell. Satan shuffled his feet.

"Well, this is awkward," he mumbled.

There was a faint whoosh from the back of the room. They all turned to see Gabriel and Michael step out of thin air.

"Who's this pair now?" Phillip frowned. "Where did they come from?"

"Good afternoon," said Gabriel, his smile as false as ever. He nodded in Satan's direction. "And look here, if it isn't the Prince of Darkness himself. We were informed you were on Earth, but we didn't believe it. And yet here you are."

"Gabriel. Michael," acknowledged Satan. "How's tricks?"

"Oh, can't complain," Gabriel shrugged. "Can't complain. Do you have the book?"

"What book?"