‘I don’t need a quest.’ Nico stood. Hearing Rachel’s prophecy again, hearing it discussed aloud, made him feel suddenly resolved. Or maybe he was just feeling contrary and cranky after enduringNico’s Greatest Nightmare Hits, vols. I and II. ‘Ihaveto go.’

Chiron’s expression was heavy and sad. Perhaps he was remembering all the other heroes he had trained over the centuries, who had saidI have to goand then never returned. ‘Nico, we are in a period of relative peace. In recent months, we have learned at great personal cost that prophecies can be manipulated or just plain malicious … No offence to Miss Dare.’

‘None taken,’ Rachel muttered. ‘I’m just happy to be spewing green gas again.’

‘It would be better for you to enjoy this time off,’ Chiron continued, ‘to heal instead of running after –’

‘You’re not the one being tormented in your dreams!’

Nico immediately wished he hadn’t blurted it out like that. IfBob really was in danger, doing whatever he could to reach out for help, thenhewas the one being tormented. No matter how painful Nico’s dreams were, Tartarus was worse.

On the other hand, if something were tormenting an immortal Titan like Bob, a being older than the gods, what chance would Nico stand against such a force?

‘Is that what you were dreaming about?’ Will’s voice stirred him from his thoughts. ‘Bob in Tartarus?’

‘Not exactly,’ said Nico. ‘At least … not directly.’

He decided to tell themeverything. He started with the long summer of frequent flashbacks and nightmares. Clearly, Mr D wasn’t as interested in that part, since he’d heard all about it already. Instead of listening, he continually tossed popcorn into the air and tried to catch it in his mouth. (He missed. A lot. Which Nico took as proof that he was not the god of hand-eye coordination.)

As soon as Nico got to last night’s greatest-hits parade of trauma, though, Mr D hung on every word.

‘Fascinating,’ Mr D said once Nico had finished. ‘I know that mortal dream worlds are confusing, elaborate and vivid, but that marathon sounds absolutelyabsurd.’

‘Thanks … I guess,’ said Nico. ‘Look, the point is that every memory, every thought and emotion in my head is screaming at me tolisten. And Bob is the one who’s calling out. It could be a trap, but I don’t think so. Bob is suffering down there. He needs my help. And Rachel’s prophecy getting stuck on repeat … I think that means the situation is getting worse. Bob is running out of time. I have to try to help him.’

Dionysus picked a fleck of popcorn from his godly teeth. ‘I thought your father made it sono onealive could enter his realm any more,’ he said. ‘You know, after that whole Doors of Death business.’

‘That doesn’t mean I shouldn’t go,’ said Nico. ‘There’s always a way into the Underworld, and my father doesn’t need to know. I have to try.’

Rachel shivered. ‘Butleave something of equal value.That’s the part I can’t wrap my mind around. Equal towhat? Bob’s life?’

Will’s blue eyes fastened onto Nico. He had that slightly worried, slightly exasperated expression he got when one of his patients didn’t follow doctor’s orders. ‘Nico, youcan’ttrade one life for another. Please tell me you’d never consider abandoning someone else in Tartarus to save Bob. Or even worse, sacrificing yourself.’

Nico tamped down a wave of irritation. Of course that thought had occurred to him, too. And his parade of nightmares, all featuring people he had lost, only heightened his fears. But he had to help Bob. He had delayed as long as he could.

‘You’re assuming this is a rescue mission,’ he said. ‘What if Bob needs my help with something butalsowants to stay in Tartarus?’

Mr D cackled. ‘Who would want tostayin that realm of nightmares?’

‘Or maybe the “equal value” thing isn’t a life for a life,’ Nico suggested weakly. ‘Maybe Bob wants to bring something back with him … like his broom or something. And he needs … a broom … of equal value.’

Will gave Nico a look that saidCome on. You don’t really believe that, do you?

‘And anyway,’ Nico forged ahead, ‘a mortal life wouldn’t be equal to the life of a Titan, would it?’

Mr D nodded thoughtfully, then glanced at Chiron. ‘The boy makes a good point. We immortals are clearly bigger-ticket items.’

Chiron frowned. ‘We know so little about all this, Nico. And Tartarus … Well, it’s not a place where any of us should venture, mortal or immortal.’

‘But I’vebeenthere,’ said Nico. ‘Did you all forget that I’m one of only three demigods who’s ever come back from that wretched place alive? And I survived there the longest. If anyone can help Bob, it’s me. I can do this on my own.’

Will marched over and grabbed Nico’s hand. ‘Yeah, that’s not happening. If you go, I’m going with you.’

Nico actually laughed. ‘No, you’re not. That’s the one thing that makes me okay with this quest – that I amnotputting you in danger.’

‘Excuse me, Noble McSacrifice,’ Will said. ‘We’rebothperfectly capable of survival.’

Chiron’s hooves clopped nervously on the floorboards. ‘But a child of Apollo in Tartarus?’