After an uneventful ride south on the 6 train, Nico and Will made their way to the southernmost edge of Central Park. Some of the leaves on the trees were beginning to turn yellow, and a light breeze‌

rustled them. Joggers and cyclists zipped along the main road as Nico guided Will towards the woodland. When Nico stopped in front of a large grouping of boulders made up of Manhattan schist, Will raised an eyebrow.

‘Where do we go next?’ he asked.

Nico pointed at the rocks. ‘Through there.’

Will regarded the giant grey slabs. ‘Am I missing something? Nico, they’re just rocks. What are we supposed to do?’

‘Oh, I am not doing anything,’ said Nico proudly. ‘I need you to sing.’

Will looked around him. ‘Is this a prank? Did you and Mr D come up with this? Are there hidden cameras?’

‘I’m honoured that you think I’m capable of orchestrating a prophecy to pull off such a thing, but, no, this isn’t a joke. This is the literal Door of

Orpheus.’

‘Oh,’ said Will. Then: ‘Oh. So it’s …’

Nico nodded. ‘One of the only remaining secret entrances into the Underworld.’

‘Which Orpheus opened with music,’ said Will. ‘Exactly,’ said Nico. ‘You think you could give it a try?’

Will took a deep breath. ‘Yeah, I can. And then … that’s it?’ ‘That’s it,’ Nico agreed. ‘Our journey can begin.’

Will turned around slowly, taking in the gorgeous Central Park trees that rose above them. ‘I don’t know how long this adventure is going to take,’

he said as he spun, ‘so first I just want to get a last look at everything. To recharge my internal battery.’

‘You’re cute when you’re nervous.’ Will came to a stop, and Nico reached out to bring him into a hug. When they let go, Nico said, ‘We’re going to be fine. Just keep in mind what Percy and Annabeth said. We’ll stick close together, okay? I know the Underworld well.’

‘I’m not that worried about you,’ said Will. ‘I’m more freaked out about how I’m going to react. It’s going to be dark, scary. I’ll be surrounded by death and sadness and misery.’

‘It’s not all bad,’ said Nico. ‘Besides, our friends will help us.’ ‘The troglodytes, you mean?’

Nico smiled, picturing the small froglike humanoids who had helped them defeat Nero. ‘We’ll be in good hands. Little webbed hands with lots of pointy claws.’

Will scratched his head. ‘Okay, I guess it’ll be nice to see them. Are you sure they’ll help us again, though?’

‘Why wouldn’t they?’ said Nico.

‘Well … we kinda destroyed their home, didn’t we?’

‘That was an accident, first of all. We had no idea the tauri silvestres had followed us!’

‘I know, but still. Wouldn’t you be mad if someone accidentally destroyed Camp Half-Blood by allowing mad bulls in to trample it?’ ‘Second of all,’ said Nico, ‘I helped the trogs find a new home.’

It took Will a moment to put the pieces together. ‘So … you’re expecting them to help us … You found them a new home … You relocated them to the Underworld?’

Nico nodded. ‘They’re even further underground now, and less likely to be found. As long as they stay out of my father’s view, they’ll be safer.’

Will shook his head, clearly mystified. ‘I don’t understand how anyone could live down there.’

A burst of irritation jolted Nico’s heart. He pressed his lips together so as not to blurt out his initial reaction, which wasn’t very kind. ‘The

Underworld isn’t what you think it is,’ he said quietly. ‘There’s a lot more to it. You’ll see.’

‘Okay,’ said Will. ‘I trust you.’

This time when he smiled it didn’t really make Nico feel better. So Nico just stepped aside and gestured at the rocks. ‘A song, please.’

Will approached the mass of boulders. He took another deep breath and started into a soft, winding melody. It was a familiar one to Nico – he’d heard Will sing it when he was using his healing abilities on someone. As Will’s voice rose and fell, Nico saw small green shoots sprout up from the ground around him. A few of them bloomed yellow flowers.

‘Well, that’s new,’ Nico said aloud to himself.

No sooner had he uttered those words than the rocks groaned and

shuddered. Will stopped singing and moved back, his eyes full of wonder, as a triangular crevice appeared, just big enough for a person to squeeze through. Inside, steps led down into deep darkness.

Will covered his mouth and nose. ‘Ugh, what’s that smell?’ The odours hit Nico then: mildew, decay, dust …

Home.

‘That’s the Underworld.’ He drew his Stygian iron sword. ‘I’ll go first.’

Will grabbed his arm. ‘Shouldn’t I use my glow-in-the-dark power for more light?’

Nico shook his head. ‘Save that for later. No sense draining yourself.’ There was a sheen of sweat on Will’s forehead. ‘If you’re sure …’

Rather than draw this out any longer, Nico reached down and grabbed Will’s hand. ‘Come on,’ he said, and he led his boyfriend into the stairwell. After the first few steps, Nico glanced back to see the shape of Will’s curls in the bright light of Central Park behind him. Then, with a loud groan, the crevice closed, and darkness swallowed the two demigods.

Only the blade of Nico’s sword cast any light: a dim purple glow that made the shadows feel even thicker.

‘Oh, wow,’ Will said. ‘It’s really dark down here.’

Nico was ready to crack a terrible joke, but right then a sensation of dread trickled over his skin. He raised his sword and peered into the gloom. The passage continued down as far as he could see, silent and empty.

‘Nico, what is it?’

Something rustled in the darkness, but behind them, where the Door of Orpheus had just closed.

Nico spun, gently pushing Will to one side, and stuck his sword in that direction.

There was nothing.

‘What’s happening?’ Will demanded.

Nico brought his sword back close to his body. He turned to Will. ‘I think you got me all amped up, is all. I’m imagining things.’

Will didn’t look convinced. Unfortunately, Nico wasn’t sure he believed it, either.

‘Okay,’ Will said. ‘But is it going to be this dark the whole time?’

‘Oh, no, not at all. We have to descend these steps for a while, but once we emerge in the Underworld, it’s … Well, you’ll see. This is the only part without any light.’ He paused. ‘At least, before we get to Tartarus.’

‘Good to know,’ Will muttered.

Nico headed down the narrow stairway, and Will followed. The steps

were much steeper than Nico would have liked, but that was mostly because he was worried for Will. He could hear his boyfriend’s footsteps echoing

around him – Will was tapping his feet on every step as if to make sure it was solid. After a few minutes, Nico paused.

‘You’re nervous,’ he said. ‘Just take the steps like you normally would.

It’ll be all right.’

Will started to answer, then stopped and looked behind him. ‘Did you hear that?’

‘Hear what?’

‘Is something following us?’

Nico didn’t hear anything this time.

‘Maybe it’s your imagination?’ said Nico. ‘This place can feel very strange the first time.’

‘Okay,’ said Will, his voice shaky. ‘Lead the way, then.’

They continued. Will had Nico stop a few more times, but in each instance Nico couldn’t hear whatever it was his companion had. So they kept going, descending deeper and deeper. Nico knew that the stairway was lengthy, so he tried to remain as calm as possible as he put one foot in front of the other, careful not to slip on the slimy steps.

It wasn’t long before impatience began to creep along Nico’s spine. He remembered descending these same steps years ago when he had led Percy to his father. The memory stung a little; he hadn’t really wanted to betray Percy, but he’d needed to know more about his own childhood, which he’d lost in the River Lethe. But Nico recalled that it had maybe taken an hour or so to traverse the entire set of steps.

Had it been an hour since Will parted the stones? Or had it been longer? Weren’t journeys supposed to feel shorter when you’d done them before?

Will echoed Nico’s thoughts. ‘How much further do we have to go?’ he asked. ‘I feel like we’ve been going down forever.’

‘I think we’ve got a bit more,’ said Nico, panting. His arm was tired from holding out his sword; the last time he’d made this journey, Percy had been the one to light the way. Funny how the older Nico got, the more he saw things about Percy differently.

‘Like, I get that it’s the Underworld,’ said Will. ‘So we have to go under the earth. But this –’

‘Shhh.’ Nico froze so suddenly that Will ran into him. ‘What is it?’ whispered Will.

‘Do you hear that?’

They both stood still. From somewhere ahead came a muted roar, like a rainstorm against a metal roof.

‘What is that?’ asked Will.

Nico smiled. ‘That’s the River Styx. We’re almost there.’

The two of them forged ahead. Nico began to take the steps two at a time. He nearly slipped on one of the stones, then steadied himself and waited for Will to catch up.

Soon, a dim grey light filled the tunnel. Nico did his best to keep his cool as they continued their descent. The roar of the Styx turned from muted to thunderous. The steps started to level out. When Nico reached the bottom of the stairwell, he emerged into a large cavern lit by glowing stalactites overhead. To his right, the River Styx spilled over the edge of a towering

climb and cascaded down a set of rocky rapids.

And in the distance … the Underworld.

Fires guttered on the ramparts of Erebos, the kingdom of death. Masses of ghosts converged on the great iron gates like a fog bank, clamouring to get in. Beyond those walls, Nico knew, lay the ghosts’ final destinies: Elysium for the lucky few who had been virtuous in life, the Fields of Punishment for the wicked, and the bleak Fields of Asphodel for the indifferent and the neutral, which was most of humanity. Beyond those fields would be Hades’s palace, all sharp angles and shadows. Nico was glad they were too far away to be able to make out any of those details. Will didn’t need to see the fates of the dead. He was already nervous enough.

Nico’s head spun with exhaustion. For a moment, he thought he saw a dark shape in his peripheral vision, something strange and menacing, but, when he turned, there was only Will.

‘Welcome to the Underworld,’ Nico said.

Will frowned, then put a hand behind his head. He was still breathing heavily. ‘Is this a joke?’

‘A joke?’ Nico was stunned. ‘Why would you call my father’s home a

joke?’

‘What are you talking about?’ ‘What are you talking about?’ ‘You said we were here,’ said Will.

‘We are!’ Nico spread his arms wide.

Will fixed his eyes on the distance. ‘Um, no, we’re not.’ Nico turned to look again and –

What?!

They were back in the stairwell. The cavernous vista of Erebos was gone.

The steps before them seemed to continue endlessly down into darkness. ‘No!’ screamed Nico. ‘What is happening? We just made it and –’ ‘Can you hear that?’ asked Will, cutting him off. ‘The river? Because I

can.’

They fell silent again. Sure enough, the distant rush of the River Styx echoed up through the tunnel.

‘I don’t understand,’ said Nico. ‘I saw the Underworld. I saw the River Styx and … and …’

Will sat down on the steps. ‘There wasn’t anything, Nico. It was just … more stairs.’

‘That’s impossible. That’s not how this is supposed to work.’ ‘Regardless, we’re still not there. Do you think your father is trying to

prevent us from entering the Underworld?’

‘No!’ said Nico. Then: ‘I don’t think so. He shouldn’t even know that we’re here.’

‘You sure about that?’ said Will.

Nico hesitated. ‘Let’s keep going. If I see the end of the tunnel again, I’ll ask if you see it, too.’

He helped Will up, and then they pushed on. Nico wasn’t positive, but it seemed like another hour passed before the sound of the Styx finally got louder and the tunnel filled with grey light once more. Nico reached back for Will, and his boyfriend’s hand slipped into his.

‘There,’ said Nico. ‘Do you see that brightness ahead?’ After a short pause, Will said, ‘Actually … yeah, I do.’

‘Okay!’ said Nico. ‘Good. Let’s keep moving.’

Moments later, as the darkness receded, Nico spotted the base of the steps.

‘Can you see that?’ said Nico, pointing. ‘Yes!’ said Will, breathless. ‘It’s the end!’

They rushed down the remaining steps and into the cavern. As before, the Styx’s waterfall roared to Nico’s right. Across the river loomed the burning ramparts of Erebos.

Nico had this whole plan in his head to explain the geography of Erebos to Will so he’d have some idea where they were heading, but when he turned to speak his heart sank.

It wasn’t just Will’s panicked expression that terrified him. Somehow their surroundings had changed again. Nico couldn’t believe it, but they now stood in the woods of Central Park in the dead of night.

His heart racing, he pivoted and stared at the blank grey wall of schist that marked the Door of Orpheus.

There was a thump behind Nico. Will had fallen to his knees in the wet grass.

‘Nico,’ he said desolately. ‘What’s happening?’

‘If I remember correctly,’ said Nico, ‘the first time I met Will was during a battle.’

‘Which one?’ Will narrowed his eyes. He still looked so weak and tired. ‘Oh, wait – was it when Octavian’s faction attacked the camp?’

‘Uh, no,’ said Nico. ‘Wasn’t that only, like … a little over a year ago?

We’ve known each other a lot longer than that.’ ‘Oh.’ Will rubbed his face. ‘Sorry, you’re right.’

Nico felt another twinge of concern. ‘Is your memory getting worse?’

Will grunted but did not answer the question. ‘You were around … before that,’ he said hazily. ‘Long before. Back around the time when … when the Battle of Manhattan …’

Nico smiled. ‘Yeah, I was. I wasn’t staying at Camp Half-Blood much, though.’

‘I remember that! And even when you were at camp it was so hard to pin you down. You wouldn’t stay put. You were … afraid. Afraid of getting

close to anyone.’

Nico was silent for a moment. ‘Sometimes I still am,’ he said. ‘Like earlier, when you were complaining that I wasn’t telling you things.’

‘Sort of.’ Will pressed his hand against his stomach. ‘I don’t know if I was being fair to you –’

‘That’s not important now,’ said Nico. ‘Let’s get through this.’

‘I hope you do not feel that I am something to “get through”,’ said Gorgyra. ‘I am not trying to make things difficult for you boys.’

For a moment, Nico had almost forgotten the nymph was there. He tried to tamp down his fear and frustration, his urge to scream Just let us go!

‘It’s a trade, right?’ he said. ‘We give you our story, and you give us a boat.’

‘If you must see it that way,’ she said. ‘Yes.’

‘I remember …’ Will coughed softly, and Nico ran his hand over his boyfriend’s back. His eyes travelled down to the gauze on Will’s leg.

It was completely soaked through with blood. ‘What do you remember?’ Gorgyra asked.

‘I remember how sad I was when you left to go find Percy,’ Will said to Nico. ‘When he disappeared.’

‘You were sad? But … did we even know each other then?’

‘Maybe not as close friends or anything, but … but I was drawn to you. Maybe it was because you were so mysterious. Maybe it was because you kept pushing everyone away whenever they tried to be your friend.’

‘Not a lot of people tried to be my friend in those days,’ said Nico. ‘That’s not true!’ said Will, and for a moment his energy seemed to come

back. ‘Plenty of us tried to be friendly to you, and you always had an excuse or a mean remark ready for us.’

‘That doesn’t sound like me,’ Nico said, trying to play it deadpan, but Will gave him a stern look. Nico laughed. ‘Okay, okay, fine. Maybe that sounds like me.’

‘We met … way before the Battle of Manhattan, actually,’ said Will, leaning against Nico. ‘You … You came into the Big House, remember?’

‘What?’ Nico scratched at his head. ‘When was this?’

‘Back when I was still training to be a field medic, with Michael Yew …’

Will fell silent, unable to finish, and that’s when the fragment of memory came back to Nico.

‘The sword fight,’ he said. ‘I’d only been at camp a couple of days. Chiron had me training with the other campers, and I went too hard.’

‘You sliced your own leg,’ said Will, smiling weakly. ‘If I remember correctly, you missed the target dummy completely because you were arguing with Chiron.’

‘I love that you seem to remember all the most embarrassing moments of my life,’ said Nico. ‘Way to go, Will!’

‘I only remember that because of what came after. The part that’s more striking … was you. In the Big House. You wouldn’t sit still, and Michael

was barking commands at you because you were bleeding everywhere, and

… and –’

‘You calmed me down,’ said Nico, and the image bloomed in his mind: a young Will Solace, his blond hair bushy and slightly unkempt, holding

Nico’s leg still, Will’s blue eyes boring into his own. ‘At least I tried,’ said Will. ‘I don’t think it worked.’

‘It did,’ said Nico. ‘Even if it was only for a moment. I was … a little difficult when I was younger.’

Will grinned. ‘Oh, only when you were younger?’ ‘Shut up.’

‘That’s news to me. You’ve never been difficult since.’

Nico shifted uneasily. He glanced over at the old nymph, who was studying the two of them with a wistful look.

‘So, is that it, Will?’ Nico asked. ‘Is that really how we met?’

‘I think so. I’m pretty sure I saw you running around Camp Half-Blood when you were originally rescued by Percy and Annabeth, but that was our first face-to-face moment.’

Nico shook his head. ‘I didn’t even realize that was you back then. But … well, I also don’t remember much about my first few weeks at the camp. I felt so out of place.’

Gorgyra sighed. ‘It seems you two have a complicated and labyrinthine connection.’

‘Would really love to never think about a labyrinth ever again,’ Nico muttered.

She smiled. ‘I find this fascinating. Sometimes mortals are not aware of the threads that bind them. You could both be wrong about the first time you met, and yet the two of you have orbited each other for so long, like heavenly bodies in the sky.’

Will squeezed Nico’s hand. ‘I like how that sounds.’

Nico studied Will’s broken fingernails, the cuts on his knuckles. He certainly felt like he was spinning through space … like he would go shooting off into the void if it weren’t for Will’s gravity.

‘Well,’ Nico said at last, ‘maybe we don’t remember the first time we

actually met, but I do remember when I considered you a friend.’ ‘Tell me,’ Gorgyra said.

Nico heard the yearning in her voice: insatiable, like the three-headed dog Cerberus begging for bones. Just one more. Just one more. Nico

worried Gorgyra would keep demanding stories, pulling on string after string, until their whole lives were unravelled at her feet.

Nevertheless, he wanted to talk about it. He looked into Will’s tired blue eyes when he spoke, not Gorgyra’s. ‘It was at camp. After … after

Octavian. When he … you know.’

Will’s face drooped. Nico knew he hated that memory: when Nico and

Michael Kahale had allowed Octavian to launch himself to his own death. ‘I remember.’

‘We had defeated Gaia. You were standing in the doorway of your cabin.’

Will laughed softly. ‘I remember that, too. I think I scolded you pretty hard.’

‘You did,’ confirmed Nico. ‘But it was the way you did it. You made it clear that you wanted me around. You said you wanted me to come to the infirmary and help, because … because you could use a “friendly face”.’

‘It was true. And you did help.’

‘You brought me closer instead of rejecting me,’ Nico said, his voice

cracking. ‘I’d never been called a friendly face. Ever. You made me rethink everything – my place in camp, my crush on Percy, my future. It took you scolding me like you were the camp director to make me realize that I was

… wanted.’

Gorgyra sniffled, then wiped her eyes. ‘You’ll have to excuse me,’ she said. ‘It is hard not to react to something like that.’

Will swayed, and Nico steadied him. ‘You okay?’ asked Nico.

‘This place,’ he said. ‘I’m so tired.’

‘I know,’ Nico said, watching apprehensively as the blood seeped across the gauze bindings on Will’s leg. He turned to Gorgyra. ‘We need to go if we’re going to reach Tartarus.’

‘Wait,’ said Will. ‘I remember something else. I know we need to go, but

… you remember what Percy and Annabeth said, about how important it is to remind each other of the world above?’

Nico frowned. ‘But we’re not even in Tartarus yet.’

‘It feels like we are,’ said Will. ‘And I know you’re worried. But just … give me this. It does make me feel better.’

Nico gazed at Gorgyra and the whispers in his mind returned: voices telling him what he already knew about himself, all his worst fears and failures.

‘All right,’ he said to Will. ‘If it helps.’

That brought a bit of colour back into Will’s face. ‘I remember when I realized … when I knew that this was more than a friendship.’

That made Nico smile despite himself. ‘I remember my moment, too.’

Will’s eyes filled with tears. ‘I think mine is different than yours.’ ‘But I know mine happened first,’ Nico said.

‘Tell me,’ Gorgyra said, moving closer to Nico and Will. ‘Tell me one more story.’

And Nico felt another string start to unravel.