Will's brow creased in worry.

"Are you sure you have to go? You deserve a break after Gaea."

"Thanks, but Dad said he's been seeing a lot of spirit activity in the city."

Will nodded solemnly. Then a small smile crept up his face.

"Hey, you called Hades 'Dad'."

Nico paused. After a while, he smirked.

"Yeah... I guess I did."

Last week had been the weirdest week of Nico's life. And that's saying something. Apparently, a really tricky spirit had escaped the Underworld. Of course, Hades put him up to catching it, but then Hades turned to the other campers. The gods of the Underworld pointed to Percy and ordered him to help Nico and then he called on Hazel. Nico had mixed feelings about Hazel coming. He loved her as much as he'd loved anyone, so what if the quest was dangerous? It was kind of silly worrying about Hazel's safety after she took on the freakin' Earth, but he was her brother.

"I think I'm all packed. I'll be back soon," Nico promised Will.

The son of Apollo didn't look happy about it. But he pulled Nico into a hug and buried his face in the son of Hades' shoulder.

"You better come back or I'm coming for you."

"Oh, no. Don't want to ignite the wrath of Apollo's son."

Will chuckled, ruffling Nico's hair.

"Stay safe."

Nico smiled, pushing past his boyfriend. The camp was still asleep, but Percy and Hazel were already waiting at Thalia's tree. They greeted him warmly. Percy cleared his throat, shaking Nico's hand.

"Hey, man-"

"Don't worry about it. No awkwardness, no dwelling. Not anymore," Nico said.

Percy gave him a grateful look before pulling away. Together, the three set out. Nico swung his backpack around, digging through until he found a map. He held it up to the early morning light and cursed in Greek.

"Amity Park's halfway across the country."

"What else is new?" Percy mumbled.

"So, Nico, what exactly are we looking for?" Hazel asked in a small voice.

Nico thought back to what his father told him.

"I think we're looking for some kind of... portal? Hades is really ticked, he says whatever it is punched a hole into the Underworld. The ghosts are finding their way out slowly but surely. Some are probably all good and helpful, but Dad wants to make sure none of the vengeful spirits escaped."

Percy bit his lip.

"Got it. Ghosts escaping is bad. So we need to find this portal and shut it down, right? Does that involve punching stuff?"

Nico and Hazel stared at him. He shrugged and continued walking, swinging his pen around. Nico ducked instinctively, watching the pen wearily.

"Watch where you swing that thing!"

"Scared of a little old pen, di Angelo?" Percy asked with a grin.

Nico gave him one of his famous evil stares. Percy just shrugged it off and continued walking ahead, leaving Nico alone with Hazel.

"Do you have any idea why Dad wanted Percy and me to come along?" Hazel asked.

Nico hated admitting when he was wrong. No matter how hard he tried, he couldn't meet Hazel's gaze.

"No..."

The Ghost King not knowing anything about his ghosts. There was probably an irony joke hidden somewhere in there. Nico's mind wandered as they trudged towards the nearest bus stop and bought tickets for Amity Park. Personally, he didn't trust any place that sounded so happy. But Hazel bought him a Happy meal. That was compensation enough. Soon, Nico's eyes started drifting. Sleep was good. He was a master of dreaming by now... okay, maybe master was a little over the top. He was barely aware of his two friends chatting away over their food.

"I don't, Danny. This seems kind of risky."

"Relax, Sam. I've done this a hundred times!"

Sam mumbled something that Danny couldn't catch over the earpiece. Tucker and Sam were down below on their scooters. It zipped along, falling a little behind Danny. Up ahead, the trees were coated in Ectoplasmic goo. Danny gave Sam a smug glance.

"See? I told you we'd find it!"

"Great! Now all you need to do is catch it."

Danny swung his thermos around, gripping it in his hand. He scanned his surroundings, looking for the monster. It had appeared out of nowhere, a beast with red scaled and glowing purple eyes. Long black claws that were as long as Danny extended out. After a couple of seconds, Danny sighed.

"I don't see it."

"All clear down here. Maybe we should call it a night. Besides, you look really tired."

Danny hadn't even noticed. He'd been so busy fighting ghosts that the adrenaline had kept him awake. Now that Tucker pointed it out, Danny could feel his whole body turning to lead.

"Yeah... sure. My parents are going to kill me. I'm past curfew again."

"All the more reason to take a break."

Danny soared over some of the buildings. He could see his friends trying to catch up. He was about to go help them when a voice stopped him.

"Hello, Daniel."

A man stepped out of a nearby shadow on a tree branch. Danny looked at the man quizzically. He was wearing a dark robe with a hood over his face. Something about this guy was... unsettling.

"Who are you?"

"Let's just say I'm a friend. An old enemy is returning. Clockwork has foreseen his inevitable arrival."

"Who are you talking about? What enemy? Freak Show? Undergrowth? It's not... Dan, is it?"

"Close but not quite. He's come to banish the ghosts. That includes you, Danny. The enemy wishes to tear you from this world forever. You'd never see your friends or family again."

Danny tensed.

"Who is he?"

"Alas, his name is unspoken. Where I come from, he's known as the Ghost King."

"Pariah Dark?"

"No, you fool. The Ghost King is a force of darkness much more powerful than Pariah Dark. He's the spawn of death and life itself. He does Death's work, bringing it wherever he goes. The creatures that hide in the night are attracted to his kind."

"Hold on a minute. Who are you and why are you telling me this?"

"I wish to see the great ghost-boy victorious in the oncoming battle. Be warned, the Ghost King does not walk alone. He travels with more of his kind. More unnatural spawn of the Earth and seas. The Son of Neptune and the Girl Who Died... I have overstayed my welcome, I fear. Death is searching for me. You have been warned, ghost-boy. Kill them before they kill you."

The man started sinking into the shadows. Danny made a desperate grab for the stranger's hand.

"Wait! Who are you? You can't just drop that on my shoulders!"

Danny's hand swept out. But instead of touching the man, he only grabbed empty air. Danny's hair fell into his face as he stared at the spot the man had been. What if a Ghost King really was coming? The man's words echoed in his head. Spawn of death and life itself. Sam and Tucker had finally reached the tree. They propped their scooters down just as Danny lightly touched the ground.

"W-we have to get ready."

"For what?"

"War's coming to Amity Park."