'He needed me.' Those silver eyes gleamed in the darkness. 'It is okay. I was tired of sweeping the palace. Come along! We are almost at a rest stop.'

A rest stop.

Annabeth couldn't imagine what those words meant in Tartarus. She remembered all the times she, Luke and Thalia had relied on highway rest stops when they were homeless demiG.o.ds, trying to survive.

Wherever Bob was taking them, she hoped it had clean restrooms and a snack machine. She repressed the giggles. Yes, she was definitely losing it.

Annabeth hobbled along, trying to ignore the rumble in her stomach. She stared at Bob's back as he led them towards the wall of darkness, now only a few hundred yards away. His blue janitor's coveralls were ripped between the shoulder blades, as if someone had tried to stab him. Cleaning rags stuck out of his pocket. A squirt bottle swung from his belt, the blue liquid inside sloshing hypnotically.

Annabeth remembered Percy's story about meeting the t.i.tan. Thalia Grace, Nico di Angelo and Percy had worked together to defeat Bob on the banks of the Lethe. After wiping his memory, they didn't have the heart to kill him. He became so gentle and sweet and cooperative that they left him at the palace of Hades, where Persephone promised he would be looked after.

Apparently, the Underworld king and queen thought 'looking after' someone meant giving him a broom and having him sweep up their messes. Annabeth wondered how even Hades could be so callous. She'd never felt sorry for a t.i.tan before, but it didn't seem right taking a brainwashed immortal and turning him into an unpaid janitor.

He's not your friend, she reminded herself.

She was terrified that Bob would suddenly remember himself. Tartarus was where monsters came to regenerate. What if it healed his memory? If he became Iapetus again ... well, Annabeth had seen the way he had dealt with those empousai. Annabeth had no weapon. She and Percy were in no condition to fight a t.i.tan.

She glanced nervously at Bob's broom handle, wondering how long it would be before that hidden spearhead jutted out and was pointed at her.

Following Bob through Tartarus was a crazy risk. Unfortunately, she couldn't think of a better plan.

They picked their way across the ashen wasteland as red lightning flashed overhead in the poisonous clouds. Just another lovely day in the dungeon of creation. Annabeth couldn't see far in the hazy air, but the longer they walked, the more certain she became that the entire landscape was a downward curve.

She'd heard conflicting descriptions of Tartarus. It was a bottomless pit. It was a fortress surrounded by bra.s.s walls. It was nothing but an endless void.

One story described it as the inverse of the sky a huge, hollow, upside-down dome of rock. That seemed the most accurate, though if Tartarus was a dome Annabeth guessed it was like the sky with no real bottom but made of multiple layers, each one darker and less hospitable than the last.

And even that wasn't the full, horrible truth ...

They pa.s.sed a blister in the ground a writhing, translucent bubble the size of a minivan. Curled inside was the half-formed body of a drakon. Bob speared the blister without a second thought. It burst in a geyser of steaming yellow slime, and the drakon dissolved into nothing.

Bob kept walking.

Monsters are zits on the skin of Tartarus, Annabeth thought. She shuddered. Sometimes she wished she didn't have such a good imagination, because now she was certain they were walking across a living thing. This whole twisted landscape the dome, pit or whatever you called it was the body of the G.o.d Tartarus the most ancient incarnation of evil. Just as Gaia inhabited the surface of the earth, Tartarus inhabited the pit.

If that G.o.d noticed them walking across his skin, like fleas on a dog ... Enough. No more thinking.

'Here,' Bob said.

They stopped at the top of a ridge. Below them, in a sheltered depression like a moon crater, stood a ring of broken black marble columns surrounding a dark stone altar.

'Hermes's shrine,' Bob explained.

Percy frowned. 'A Hermes shrine in Tartarus?'

Bob laughed in delight. 'Yes. It fell from somewhere long ago. Maybe mortal world. Maybe Olympus. Anyway, monsters steer clear. Mostly.'

'How did you know it was here?' Annabeth asked.

Bob's smile faded. He got a vacant look in his eyes. 'Can't remember.'

'That's okay,' Percy said quickly.

Annabeth felt like kicking herself. Before Bob became Bob, he had been Iapetus the t.i.tan. Like all his brethren, he'd been imprisoned in Tartarus for aeons. Of course he knew his way around. If he remembered this shrine, he might start recalling other details of his old prison and his old life. That would not be good.

They climbed into the crater and entered the circle of columns. Annabeth collapsed on a broken slab of marble, too exhausted to take another step. Percy stood over her protectively, scanning their surroundings. The inky storm front was less than a hundred feet away now, obscuring everything ahead of them. The crater's rim blocked their view of the wasteland behind. They'd be well hidden here, but if monsters did stumble across them they would have no warning.

'You said someone was chasing us,' Annabeth said. 'Who?'

Bob swept his broom around the base of the altar, occasionally crouching to study the ground as if looking for something. 'They are following, yes. They know you are here. Giants and t.i.tans. The defeated ones. They know.'

The defeated ones ...

Annabeth tried to control her fear. How many t.i.tans and giants had she and Percy fought over the years? Each one had seemed like an impossible challenge. If all of them were down here in Tartarus, and if they were actively hunting Percy and Annabeth ...

'Why are we stopping, then?' she said. 'We should keep moving.'

'Soon,' Bob said. 'But mortals need rest. Good place here. Best place for ... oh, long, long way. I will guard you.'

Annabeth glanced at Percy, sending him the silent message: Uh, no. Hanging out with a t.i.tan was bad enough. Going to sleep while the t.i.tan guarded you ... she didn't need to be a daughter of Athena to know that was one hundred percent unwise.

'You sleep,' Percy told her. 'I'll keep the first watch with Bob.'

Bob rumbled in agreement. 'Yes, good. When you wake, food should be here!'

Annabeth's stomach did a rollover at the mention of food. She didn't see how Bob could summon food in the midst of Tartarus. Maybe he was a caterer as well as a janitor.

She didn't want to sleep, but her body betrayed her. Her eyelids turned to lead. 'Percy, wake me for second watch. Don't be a hero.'

He gave her that smirk she'd come to love. 'Who, me?'

He kissed her, his lips parched and feverishly warm. 'Sleep.'

Annabeth felt like she was back in the Hypnos cabin at Camp Half-Blood, overcome with drowsiness. She curled up on the hard ground and closed her eyes.

XXII.

ANNABETH.

LATER, SHE MADE A RESOLUTION: never EVER sleep in Tartarus.

DemiG.o.d dreams were always bad. Even in the safety of her bunk at camp, she'd had horrible nightmares. In Tartarus, they were a thousand times more vivid.

First, she was a little girl again, struggling to climb Half-Blood Hill. Luke Castellan held her hand, pulling her along. Their satyr guide Grover Underwood pranced nervously at the summit, yelling, 'Hurry! Hurry!'

Thalia Grace stood behind them, holding back an army of h.e.l.lhounds with her terror-invoking shield, Aegis.

From the top of the hill, Annabeth could see the camp in the valley below the warm lights of the cabins, the possibility of sanctuary. She stumbled, twisting her ankle, and Luke scooped her up to carry her. When they looked back, the monsters were only a few yards away dozens of them surrounding Thalia.

'Go!' Thalia yelled. 'I'll hold them off.'

She brandished her spear, and forked lightning slashed through the monsters' ranks, but as the h.e.l.lhounds fell more took their place.

'We have to run!' Grover cried.

He led the way into camp. Luke followed, with Annabeth crying, beating at his chest and screaming that they couldn't leave Thalia alone. But it was too late.

The scene shifted.

Annabeth was older, climbing to the summit of Half-Blood Hill. Where Thalia had made her last stand, a tall pine tree now rose. Overhead a storm was raging.

Thunder shook the valley. A blast of lightning split the tree down to its roots, opening a smoking crevice. In the darkness below stood Reyna, the praetor of New Rome. Her cloak was the colour of blood fresh from a vein. Her gold armour glinted. She stared up, her face regal and distant, and spoke directly into Annabeth's mind.

You have done well, Reyna said, but the voice was Athena's. The rest of my journey must be on the wings of Rome.

The praetor's dark eyes turned as grey as storm clouds.

I must stand here, Reyna told her. The Roman must bring me.

The hill shook. The ground rippled as the gra.s.s became folds of silk the dress of a ma.s.sive G.o.ddess. Gaia rose over Camp Half-Blood her sleeping face as large as a mountain.

h.e.l.lhounds poured over the hills. Giants, six-armed Earthborn and wild Cyclopes charged from the beach, tearing down the dining pavilion, setting fire to the cabins and the Big House.

Hurry, said the voice of Athena. The message must be sent.

The ground split at Annabeth's feet and she fell into darkness.

Her eyes flew open. She cried out, grasping Percy's arms. She was still in Tartarus, at the shrine of Hermes.

'It's okay,' Percy promised. 'Bad dreams?'

Her body tingled with dread. 'Is it is it my turn to watch?'

'No, no. We're good. I let you sleep.'

'Percy!'

'Hey, it's fine. Besides, I was too excited to sleep. Look.'

Bob the t.i.tan sat cross-legged by the altar, happily munching a piece of pizza.

Annabeth rubbed her eyes, wondering if she was still dreaming. 'Is that ... pepperoni?'

'Burnt offerings,' Percy said. 'Sacrifices to Hermes from the mortal world, I guess. They appeared in a cloud of smoke. We've got half a hot dog, some grapes, a plate of roast beef and a package of peanut M&M's.'

'M&M's for Bob!' Bob said happily. 'Uh, that okay?'

Annabeth didn't protest. Percy brought her the plate of roast beef, and she wolfed it down. She'd never tasted anything so good. The brisket was still hot, with exactly the same spicy sweet glaze as the barbecue at Camp Half-Blood.

'I know,' said Percy, reading her expression. 'I think it is from Camp Half-Blood.'

The idea made Annabeth giddy with homesickness. At every meal, the campers would burn a portion of their food to honour their G.o.dly parents. The smoke supposedly pleased the G.o.ds, but Annabeth had never thought about where the food went when it was burned. Maybe the offerings reappeared on the G.o.ds' altars in Olympus ... or even here in the middle of Tartarus.

'Peanut M&M's,' Annabeth said. 'Connor Stoll always burned a pack for his dad at dinner.'

She thought about sitting in the dining pavilion, watching the sunset over Long Island Sound. That was the first place she and Percy had truly kissed. Her eyes smarted.

Percy put his hand on her shoulder. 'Hey, this is good. Actual food from home, right?'

She nodded. They finished eating in silence.

Bob chomped down the last of his M&M's. 'Should go now. They will be here in a few minutes.'

'A few minutes?' Annabeth reached for her dagger, then remembered she didn't have it.

'Yes ... well, I think minutes ...' Bob scratched his silvery hair. 'Time is hard in Tartarus. Not the same.'

Percy crept to the edge of the crater. He peered back the way they'd come. 'I don't see anything, but that doesn't mean much. Bob, which giants are we talking about? Which t.i.tans?'

Bob grunted. 'Not sure of names. Six, maybe seven. I can sense them.'

'Six or seven?' Annabeth wasn't sure her barbecue would stay down. 'And can they sense you?'

'Don't know.' Bob smiled. 'Bob is different! But they can smell demiG.o.ds, yes. You two smell very strong. Good strong. Like ... hmm. Like b.u.t.tery bread!'

'b.u.t.tery bread,' Annabeth said. 'Well, that's great.'

Percy climbed back to the altar. 'Is it possible to kill a giant in Tartarus? I mean, since we don't have a G.o.d to help us?'

He looked at Annabeth as if she actually had an answer.

'Percy, I don't know. Travelling in Tartarus, fighting monsters here ... it's never been done before. Maybe Bob could help us kill a giant? Maybe a t.i.tan would count as a G.o.d? I just don't know.'

'Yeah,' Percy said. 'Okay.'

She could see the worry in his eyes. For years, he'd depended on her for answers. Now, when he needed her most, she couldn't help. She hated being so clueless, but nothing she'd ever learned at camp had prepared her for Tartarus. There was only one thing she was sure of: they had to keep moving. They couldn't be caught by six or seven hostile immortals.