As Nico slept, Will ran his fingers through his boyfriend’s dark hair.‌

He wasn’t alarmed that Nico had passed out. He knew Nico

would need a serious nap after summoning so many dead. In fact, Will was feeling strangely upbeat and excited. When Nico woke, Will could reveal that – ta-da! – he had brought Kit Kat bars. The candy did wonders to help Nico recuperate after shadow-travel, so Will had made sure to stow some in his knapsack, carefully sealed in an airtight bag labelled IN CASE OF EMERGENCY, EAT CHOCOLATE.

He clung to that idea: he could help Nico. He could contribute to this quest. He was more than just a powerless child of sunlight in a death pit of eternal gloom.

Because otherwise he wasn’t sure he could handle what was happening to them.

They were actually in Tartarus. In every direction, the desolate landscape stretched as far as Will could see – the terrain drenched in the colour of blood from the thick, gelatinous clouds that hung overhead. Did it rain here?

He did not want to know the answer. Having fallen through those clouds, he did not want to experience their version of a thunderstorm.

The plains were pockmarked with craters, as if Tartarus got a lot of meteor strikes. A hundred metres from the banks of the Acheron, a craggy red hill was covered in sickly orange bubbles, almost like …

Almost like zits.

These were the regeneration blisters Nico had told him about – the pus-filled pods from which monsters were reborn.

Goosebumps rippled up Will’s arms. This place was wrong.

When he breathed, the air felt sticky. Not like humidity – more like melted ice cream running down his hand in the summer. And the smell … It made him think of rotten eggs left out in the sun, then blended with dog poop, then put back out into the sun.

It also hurt. The air hurt.

Will felt a new level of sympathy for young Harley back at Camp Half-Blood, who struggled with asthma. Will wondered if this was how he felt during a severe attack. The idea of standing up, much less hiking across this horrible landscape, was enough to bring Will to tears.

Nico stirred. Will thought he might be rousing, but instead he turned and settled again.

Will wondered how long he should let him sleep. He felt terribly exposed sitting next to a bright white boat in an otherwise-monotonous red-orange landscape. He wasn’t sure what to be on the lookout for, or where danger might come from next, but Nico needed rest.

So Will kept watch. And while Tartarus was deep beneath the land of the dead, he discovered it was full of life.

In the crimson clouds overhead, something with enormous wings flapped by. A flock of smaller somethings chased after it, fluttering and screeching. In the distant hills, just at the edge of Will’s vision, shadows moved across the ridgelines, and Will couldn’t help thinking about the packs of slavering wolves Nico had described.

Every so often, the land itself grumbled like it had indigestion. Will wouldn’t have been surprised if that were the case, given the number of monsters it was constantly spitting out.

Somewhere in this nightmarish world, Bob needed their help.

Will shivered. He didn’t get how this place could be so hot and still make him feel so cold.

After a while, his legs started to fall asleep. As gently as possible, he moved Nico’s head off his thigh and onto his knapsack. Nico barely stirred.

Will stood up and stretched his legs until the pins and needles faded.

Exhaustion tugged at the edge of Will’s consciousness, but he had to stay awake, and he didn’t want to wait around doing nothing. He already felt terrible about how much Nico had been forced to look after him in the

Underworld. Will wasn’t used to that. He was the caretaker and the healer. It was literally his job as a child of Apollo.

And yet all the powers that made up Will’s sense of self were so limited here. He couldn’t even heal himself effectively. It was only due to rest and Gorgyra’s kindness that his bleeding had stopped. Speaking of which, he

should probably change the bandages, but …

He glanced down at Nico, snoring softly, and completely unsheltered.

Will had another idea. He walked over to the boat. He put his hands on the gunwale, then squatted and gave it an experimental tug. He didn’t want to strain himself – Nico would not appreciate it if Will reopened his wounds – but the hull was surprisingly light. It was good nymph workmanship, just like the canoes at camp.

Will went to work as quietly as he could. He collected rocks and bones –the plentiful building supplies of Tartarus – and made a low wall near where Nico was lying. The effort left him winded and sweaty, but it felt good to be doing something productive. Finally, he was able to turn over the boat, resting the starboard gunwale lengthwise against his wall, and – voilà! – he had constructed a crude shelter for Nico with an upside-down boat for a roof. It wasn’t much better than a lean-to, but if those clouds did decide to rain blood, acid, poison or some other vile liquid, at least they would have

some cover.

Will was pleased with himself. He imagined Nico waking up and being amazed. Will could say, Welcome home, honey!

The idea was so ridiculous it made him feel giggly again, but also warm and satisfied. He tried to hold on to those sensations. Even feelings were hard to come by here – unless they were something akin to despair or anger or fear. Those came easily. And how could they not? Will was in a place that seemed to spend every moment thinking up new ways to kill him.

Wasn’t that how Annabeth had described Tartarus? For a brief moment, Will wished she and Percy were with them, but then he discarded the thought. He wouldn’t wish this place on his worst enemy …

And, just like that, his despair came creeping back. They had no idea where Bob might be.

Their only lead was to find the giant Damasen’s hut, but it wasn’t like there were signposts here in Tartarus for Menoetes’s suggested trail. No maps or travel guides. Will tried to imagine what a tourist brochure would

look like. Come visit the geysers of suffering! Free tours of the acid-rain fields!

He didn’t know where to go. His boyfriend was out cold. He didn’t know what he was supposed to do aside from build houses out of rocks and boats. And on top of everything else … Oh, gods, he’d accused Nico of murder, hadn’t he? All his deepest grievances, and his guilt about Octavian’s death, had come pouring out when they navigated the Acheron.

When Nico woke up, Will would have to apologize. They’d have to talk it through.

They could get past it. They had bigger problems to deal with. But Will’s disappointment in himself was enough to trigger an emotional landslide.

The sheer absurdity of this quest hit him in full force. They never should have come here, at least not without more support. And if – a big if – they somehow managed to find Bob and rescue him, how were they supposed to climb back out of Tartarus?

There were so many unknowns. They piled up like the bones Nico had

summoned to break their fall. Will knew nothing. All he could do was wait for Nico to wake up and tell him what to do, then lug Will across Tartarus like an overstuffed duffle bag.

Heat rushed to his face. He’d been a huge burden on Nico since they’d entered the Door of Orpheus, and that wasn’t fair. This quest was already a terrible gamble for Nico. He shouldn’t have to take care of Will on top of everything else.

Will was a counsellor. A leader! He was supposed to take the initiative.

A thought nudged his mind, just a gentle push in a new direction. He gazed again at the closest hill, dotted with its orange blisters.

It was only a hundred metres away. Will calculated that he could make it to the top and back in less than five minutes, without Nico ever being out of his sight. At least that would allow him to gather some information – maybe get a better view of their surroundings and find out more about those regeneration pods. As a healer, he had to admit they fascinated him. Who knows? They might have healing applications for demigods.

He glanced at the boat one more time, then pulled his hood over his head.

He’d have to be quick, but this was doable.

Will hummed to himself as he started walking. His legs were still sore, but they weren’t that bad. The worst part was the noxious air coating the inside of his throat and nose every time he breathed. He pulled the

drawstrings of his hoodie, yanking it tight enough to form a makeshift mask. That helped a little bit, and it reminded him of feeling like a turtle …

Had that been yesterday? How did time pass down here?

His aching intensified as he started to climb the hill. The red soil glittered and crunched under his feet like broken glass, and Will decided he didn’t dare stumble here.

Keep a lookout, he told himself. Stay vigilant.

He glanced back to check on the boat. He felt a brief stab of anxiety when he didn’t see it … but no. The boat was exactly where he’d left it.

Nico was safe. Will had just been looking too far downstream. The terrain was so disorientating here. Will would have to remember that.

He started up the hill again. As he approached the first regeneration blobs, he realized they were a lot creepier up close. He could see the dark silhouettes of monsters floating inside, and every time they moved, the bubbles pulsated and shook. Nico’s description of them – as zits – wasn’t quite right. These blisters were more like embryonic sacs, and they were very much alive.

Fascinated, Will squeezed himself between two of the pods, trying his best not to make contact. A terrible heat emanated from the protrusions, and he stopped to remove his hoodie and stuff it into his knapsack. After a few more steps, he realized that the pods were clustered more densely towards the summit, which made climbing really hard.

Still, he had to keep going. A few more metres and he should have a much better view of their surroundings.

He was almost to the top when he slipped on a patch of loose gravel. His back heel slid straight through the membrane of a pod.

It was easily the grossest sensation Will had ever felt, like stepping in a rotten pumpkin that happened to be filled with battery acid. He pulled his foot free, but the yellowish goo had coated his shoe and was smoking

against his bare shin.

He yelped and kicked, then pulled out a sleeve of his hoodie and used it to wipe away as much of the goo as possible. Unfortunately, his shin was

already red and blistering. So much for the goo having healing applications

…

He had no time to recover, though. From the punctured blister something small, dark, and slimy clawed its way out of the fluid. It lifted its sticky head and let loose a terrible squawk.

Will froze. ‘You’re kidding me!’

Because he recognized that Celestial bronze beak, those beady red eyes, those razor-sharp feathers. He was face to face with a goo-covered Stymphalian bird.

The demon bird cocked its head as it studied Will. It cooed – a normal pigeon-y coo, that is – then tapped the ground with its beak.

‘Nice birdie.’ Will held up his palm. He meant it as a gesture of peace, but belatedly he worried he might be signalling Here! Exposed flesh to eat! ‘Stay right there.’

The bird cooed again, then hopped closer to Will.

He pulled his knees to his chest. His heart was hammering, but he tried to stay calm. ‘Sorry if I woke you early. Really, I love demon pigeons. You’re cute, aren’t you, buddy?’

The bird screeched – a sound like metal nails on a chalkboard – and then leaped at Will.

He kicked at it and rolled sideways.

But when he got to his feet and crouched in a defensive stance, the bird was nowhere to be seen.

Will scanned the hill, certain that the bird would swoop down on him at any second. Where was it? Had it simply flown off?

Then he heard a sickening gurgle, and his stomach dropped. He turned

slowly towards the regeneration blister and found the bird staring at him … Along with two other birds that had just been extruded from the break in

the membrane. More dark shapes were inside the pod, stirring and

wriggling towards the exit that Will’s foot had conveniently provided.

Of course. He couldn’t just wake up one Stymphalian bird. He had to go and wake up an entire flock – the very same creatures that had tormented him and his mom in Washington Square Park.

‘Oh, no,’ he said. ‘I – I don’t suppose we can talk about this.’

The demonic birds screeched and lifted into the blood-red sky, more and more of them pouring out of the broken pod.

Will tried to run up the rest of the slippery slope. He darted to the left and dodged more bubbles, hoping to put some distance between him and the

winged terrors.

He had never wanted to be a fighter. Not in the Battle of Manhattan or the Siege of Camp Half-Blood, not even in Nero’s tower. He loved being a healer.

Yet here he was, alone on a hill in Tartarus, surrounded by vicious Stymphalian birds. Why, oh why hadn’t he honed his archery skills? Why had he not considered that he might get separated from Nico and would need his own weapon?

He heard fluttering above. Close above. He dived to the ground, but it

was pointless. A group of birds attacked him, pecking his scalp and tugging at his clothes.

‘No!’ he cried out. ‘Go away! Find someone else to attack!’

But there was no one else, and even if his screams woke up his boyfriend, Nico would never be able to reach him in time to help. As Will tried to crawl away, he realized he never should have left Nico’s side. He shouldn’t have been so arrogant and reckless.

The Stymphalian birds pulled at his sleeves, his shoes, the hems of his

shorts. His backpack was ripped off his shoulders. Will curled up as tightly as he could, but he knew it wouldn’t help. Those bronze beaks could tear him to shreds.

But … why weren’t they?

More and more of the creatures swirled around him, cawing with

exultation, pecking at his clothes. And then … Will was rising. The cursed birds weren’t trying to kill him. They were lifting him off the ground.

He screamed, but it did no good.

He swatted at the birds and kicked his legs, but the flock was everywhere now – a living cloud of angry feathers and claws.

As they carried him up and away – a metre off the ground, five, ten, fifteen – he looked down in despair, hoping Nico had heard the noise and was coming to his rescue. But instead he saw something even more terrifying than his own predicament.

Crouched near the boat, as if getting ready to lift it, was a tall creature with furry legs and pointy horns.

Then Will was swallowed in a black storm of feathers and transported into the poisonous skies of Tartarus.