Nico found himself at Camp Half-Blood.‌

He stood outside the front door of the Big House, hand raised,

cheeks stinging from the cold. As his knuckles rapped the door, he realized which moment he was reliving. He knew what waited for him on the other side of that door: another memory he very much preferred not to visit. But, like in all his nightmares, he had no choice.

He pushed his way inside.

His gaze jumped anxiously from Chiron to Annabeth, from Silena Beauregard to Charles Beckendorf, from the Stoll brothers to …

Percy Jackson.

All of them were gathered in the living room, staring glumly at the carpet or the fire crackling in the hearth.

Nico didn’t want to ask what was wrong. He already knew the answer.

Still, the words spilled from his mouth. ‘Hey! Where’s my sister?’

The air seemed to leave the room, just as it had on the actual day. The blood drained from Percy’s face.

He stood, putting out his palms, as if Nico were a feral cat he was trying to approach. ‘Hey, Nico … listen to me, okay?’

The memory was so raw, so agonizing. But Nico managed to regain control, wresting himself from the grip of the dream logic. ‘NO!’ he

screamed. ‘I am not reliving this nightmare again!’

Chiron swivelled his wheelchair towards him. ‘You have to, young demigod,’ he said, but his voice was wrong. It now belonged to Epiales. ‘You can’t escape this.’

Nico sneered. He marched across the room, pushing aside Percy Jackson, and loomed over Chiron. ‘You’ve been behind all the horrible dreams I’ve been having for months, then. Why do you keep telling me to listen? What does it have to do with Bob?’

Chiron’s face twisted in confusion, and Epiales spoke through him again. ‘For months? But –’

‘You can’t manipulate me.’ Nico unsheathed his sword. ‘This isn’t real, and you can’t hold me here forever.’

Chiron/Epiales scratched their chin, apparently unfazed by the Stygian iron blade in their face. ‘Wait, can we go back to you claiming I’ve been sending you dreams for months? I certainly wish I had been. That would have been so fun! But, no, Mother only required that I intercept you and

Will Solace once you passed through the Door of Orpheus. Also … who is Bob?’

Nico’s sword hand wavered. Around him, the images of his fellow demigods flickered like faulty lightbulbs.

‘You know exactly who I’m talking about,’ he said, though he couldn’t muster much conviction. ‘Who is Mother?’

Epiales smiled through Chiron’s face. ‘Oh, some questions you don’t want answered, Nico di Angelo …’

Then the floor split, and Nico fell into the void.

Will’s eyes fluttered open.

It was dark, which didn’t tell him much; all the Underworld was dark. But, as his vision adjusted to the shadows, he realized he was lying on a thin stretch of brickwork at the edge of a sewer trench.

‘Jump the cow?’ said a voice to his right. ‘That was your plan?’

Will turned his head, and there she was: Meg McCaffrey, her dark hair unkempt and her face sweaty. Her rhinestone-studded cat-eye glasses

sparkled in the gloom.

‘Meg?’ he said. ‘How did you get here?’

She scowled at him. ‘Same way as you, Sun Boy. Your boyfriend helped us.’

Will’s heart dropped when he looked where Meg was pointing. Nico was curled up asleep in the tight space they were sharing. Will crawled over to

him.

‘Nico!’ He cupped his hands around his boyfriend’s face. ‘Nico, are you okay?’

‘He’ll be fine, assuming you can heal him.’

Will looked up at a bedraggled teen boy with acne and ill-fitting clothes. Lester Papadopoulos. Aka the Ex-God Formerly Known as Apollo.

AKA Dad.

But how was he back? Apollo had been returned to godhood at the end of the summer, and Will had expected that it would be years before he saw his father again, if ever.

Will’s head was full of a terrible fog, something thick and soupy that made it difficult to sort between the present and his memories. He had lived through this moment before, hadn’t he? So why was he living it again?

He vaguely remembered being in another place … a dark smoky figure towering over him –

‘Help him.’ A third voice broke through Will’s thoughts. Rachel Elizabeth Dare was staring at him expectantly. ‘I thought you were a healer.’

‘And I thought you were one of my children,’ said Lester, crossing his arms. ‘My children are supposed to be the best doctors.’

‘What use are you,’ Meg asked, her voice sharper than before, ‘if you can’t even fix your own boyfriend?’

No, Will thought. This isn’t right. There was a prophecy … His mind grasped for it. Was he … Was he supposed to leave something behind? But his companions were all staring at him, waiting for him to do his job.

Will dug in his pockets furiously. Where was his supply of Kit Kats? He pulled his pockets inside out.

They were empty.

When he looked down at Nico again, he seemed even paler than usual. ‘Nico, wake up,’ Will pleaded. ‘You have to be okay.’

‘Does he?’ jeered Rachel, her red hair falling over her face. ‘Come on, Will Solace. Heal him.’

‘Heal him!’ Lester ordered, and it was the command of a god, not of a seventeen-year-old.

The melody escaped Will’s lips. He sang in Greek, caressing Nico’s forehead, hoping beyond hope that colour would return to his boyfriend’s face.

‘You’re supposed to be good at this,’ Meg grumbled.

Will’s hands began to glow, dully at first, then brighter, until his body illuminated the sewer culvert. He pressed his fingers into Nico’s cheeks, tears running down his face, but Nico wasn’t responding. In fact, the colour in Nico’s whole body was disappearing, so he looked like he belonged in an old television show.

‘I can do this!’ Will said, sobbing. ‘I can save you!’ Nico’s eyes opened, but they were milky white. ‘No,’ he said, smiling coldly. ‘You can’t.’

He grabbed Will’s wrist. Will yelped in protest. His light began to drain away, flowing into Nico’s body. As Nico’s colour returned, he sat up and pushed Will to the ground while the others looked on approvingly.

‘Finally, you’re good for something,’ Lester said. ‘You make an excellent spare battery.’

Will was unable to breathe, his life draining away, his colours vanishing until his fingers were as grey as ash.

He tried to cry out, to plead with Nico, but he made no sound … Then Nico released his grip, and Will tumbled into darkness.

As Nico fell, he could sense something waiting for him below in the darkness, much like he could sense the dead lurking beneath the soil. This time, instead of waiting to land in another dream, he lashed out, grabbing the presence with both hands, and was rewarded with a startled, piercing shriek.

The dream world fractured.

Nico opened his eyes and found his fingers clamped around Epiales’s throat. Nico was free.

Epiales thrashed, two of their appendages flinging Nico across the ground. Nico rolled, avoiding another set of appendages that were trying to grab him. His hand found the scabbard of his sword, and he yanked it free, pointing the glowing blade at Epiales.

The demon roared. ‘Why are you making this so difficult? Who doesn’t

want to sleep all the time?’

‘Your mistake was thinking you could keep me down in my own home,’ Nico said with a sneer.

Then he jammed his sword into the dirt.

All around him, the dead rose – flesh and rotted clothes clinging to the

skeletons, dim light glowing in the eye sockets of the cracked skulls, rusted swords clutched in bony fingers. But there were more than just humans here. This was the Underworld, after all. A pack of skeletal wolves snarled at Epiales. A dragon-like creature the size of a car flicked its vertebral tail, snapping its long jaws.

‘I can summon as many of them as I need to,’ said Nico. ‘This won’t go the way you want.’

Epiales laughed, a high, giddy sound. ‘Nico, you’re not thinking correctly.’

The demon waved their right hand, and in an instant every skeleton crumpled onto the ground, fast asleep.

‘I’m the demon of nightmares, silly,’ said Epiales. ‘And the dead can dream just like everyone else.’

They raised both their hands, and the ground cracked beneath Nico’s feet.

He scrambled backwards as more of the dead clawed their way to the

surface – humans, beasts, monsters. But these hadn’t been summoned by

Nico, and they weren’t skeletons. These beings flickered in and out of view, drifting over the ground like they were both there and not there.

‘How could you even think to frighten or harm me?’ Epiales continued. ‘I bring darkness to the minds of others. I can summon anything – dead, living, real, imaginary – to torment you!’

There was a terrible, terrible roar behind Nico, and when he spun around he saw an impossible creature.

A manticore, with the body of a lion, the tail of a scorpion, and the face of a man.

But this wasn’t just any manticore. This one had the short grey hair, the mismatched blue and brown eyes, and the hawkish face of Dr Thorn, Nico’s old vice principal from Westover Hall. Suddenly Nico felt like a helpless little kid again. He backed away, unable to master his fear.

Epiales laughed, their mouth full of black teeth. ‘You can’t defeat me, Nico di Angelo. I am darkness. Yours, Will’s, everyone’s.’

Their every appendage rose into the air, then whipped towards Nico and his lifted sword.

Will rolled onto his stomach, his hands now free, and the stench of the

Underworld hit his nose. He nearly gagged, but there, just ahead of him, he saw the demon Epiales, surrounded by a host of terrible creatures.

He saw the manticore and knew exactly who it was from the stories Nico had told him.

He heard Epiales’s warning: ‘You can’t defeat me. I am darkness. Yours, Will’s, everyone’s.’

Epiales’s horrible appendages rose and … Will understood.

Of course Nico had not abandoned him at the River Styx, or drained the light out of him when Will tried to heal him.

They were just nightmares – Epiales playing on his worst fears, just as they were now doing to Nico.

And Will wasn’t going to lie there and let anyone hurt his boyfriend.

Will didn’t think. He rose to his feet and shouted in defiance and, when he did so, his skin glowed brighter than ever before. Light erupted from his chest, slicing through the dark appendages that whipped at Nico.

He watched in shock as they fell to the ground and flopped there.

Epiales looked just as shocked. As the manticore poofed out of existence, the demon of nightmares stared at their severed appendages, which

wriggled like long, lanky eels out of water.

‘Ow,’ they said, staring at Will, eyes wide. ‘Did you just –?’ ‘Will?’ Nico pushed himself up on one elbow. ‘What was that?’

‘No, seriously, what was that?’ said Epiales, folding their remaining appendages protectively behind them. ‘Mother never told me about … whatever that was.’

‘It’s light,’ said Will, breathing heavily, a line of sweat trickling down his left temple. ‘You said you were darkness. Well, I’m the opposite.’

Epiales inched back, whimpering pitifully. Suddenly they seemed more like a scolded child than a demon. ‘Mother is going to be so disappointed in me. She already thinks I’m not as powerful as I could be. Now you’re probably going to defeat me, aren’t you?’

‘I kinda have to,’ Will said. ‘We have a quest to complete, you know.’ The demon stomped a foot. ‘You demigods always have to ruin things!

And no one appreciates what I offer the world.’

‘For what it’s worth,’ said Nico, struggling to his feet, ‘your nightmares

… they’re really good.’

‘Totally,’ said Will. ‘I believed they were real until about two minutes ago.’

At that, Epiales perked up, their appendages fluttering. The ones Will had severed were already starting to regrow. ‘Really? You think so?’

Nico nodded. ‘Definitely high-grade material.’

‘Well, shucks,’ said Epiales. ‘No one has ever told me that.’

‘And you’re sure you weren’t the one sending me nightmares before we entered the Underworld?’

‘Very sure,’ said Epiales. ‘I would claim it in a heartbeat if it had been me.’

Will frowned at his boyfriend, wondering what conversation he’d missed, but a different question rose to the surface of his thoughts. ‘Who is your mother?’ he asked the demon.

Epiales merely smiled. ‘You’ll find out soon enough. Just go ahead and blast me with your light. Get it over with.’

Will hesitated. It somehow seemed wrong to blast someone on request.

But Epiales was a demon. They’d regenerate down in Tartarus anyway,

starting the cycle all over again. They were a monster; Will was a demigod. That’s how it worked, right?

Epiales must have sensed his reluctance. They raised their appendages and roared at Will, and, just like that, it happened again. Will’s fear guided him: light burst from his chest, smacking Epiales in the face, and with a piercing scream the demon dissolved.

Nico stared at him in disbelief. ‘Will …’

Will drew a shaky breath. His eyes were swimming with exhaustion. He worried that he’d finally done something that would make Nico realize they were simply, irreconcilably too different. ‘Yes?’

Nico didn’t seem able to talk at first. Then: ‘You are a legitimate demigod Care Bear.’

Will’s top lip trembled. He fell to his knees. Then he bent over in loud, raucous laughter until tears poured from his eyes.

‘You’re so weird.’ Nico crawled over, pulled Will to him and silenced his laughter with a tender kiss. ‘Please keep being my own personal Care Bear, though.’

‘Always,’ said Will.

And then he promptly passed out.