‘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 begoodat 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 wasfree.

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 sodifficult? Whodoesn’twant 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.’

Epialeslaughed, 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 raisedboththeir 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 andnotthere.

‘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 justanymanticore. This one had the short greyhair, 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. Iamdarkness. Yours, Will’s,everyone’s.’