Sure enough, both Harry and Quirrell were standing in the final chamber. Neither of them noticed Nico's entrance; Quirrell was focused on a large mirror and Harry was focused on Quirrell. With a start, Nico realized the mirror was the same one he'd encountered at the beginning of the school year.

"Next to him, who would suspect p-p-poor, st-stuttering P-Professor Quirrell?" Quirrell was saying.

"And…Nico?" Harry asked hesitantly. Nico ducked behind a column and out of sight.

"Nosy boy. Saw through my act right from the start," Quirrell said irritably. "He found that troll before I'd even had the chance to investigate the Stone's protections."

"You mean…he's not part of this? He really was trying to protect the Stone?"

"I cannot speak to his motives. But it was very helpful of him to antagonize you and divert your suspicions."

Nico frowned. It didn't sound like Harry and Quirrell were allies…it sounded like Harry really had come here for the same reason as Nico.

"But…the Quidditch match. He tried to kill me."

"No, no, no. I tried to kill you. If that smokescreen hadn't broken my eye contact, I would have succeeded—even with Snape muttering his countercurse, trying to save you."

"Snape was trying to save me?"

"Of course," Quirrell said casually. "Why do you think he wanted to referee your next match? He was trying to make sure I didn't do it again. Funny, really…he needn't have bothered. I couldn't do anything with Dumbledore watching…and what a waste of time, when after all that, I'm going to kill you tonight."

Quirrell snapped his fingers. Ropes sprang out of thin air and tightly bound Harry.

"Now, wait quietly, Potter. I need to examine this interesting mirror."

Nico considered his options. He could summon his sword and cut Harry free, but he decided against it—Stygian Iron was as lethal to mortals as monsters, and if he so much as nicked Harry by accident, that would not be good. He could attack Quirrell, but he was reluctant to kill a mortal. He could try using his wand, but he knew he didn't know nearly enough magic to take on a fully-trained wizard. His sword was his best option.

Nico summoned his sword and stepped out of hiding. "Hello, Professor."

Quirrell looked back at him and started in mild surprise. "I wondered if you'd come here as well. I must say, I did not expect your choice of weapon."

Nico hefted the sword. "Did you really believe Hermione's story about my cat? Vescia wouldn't hurt a fly. I killed that troll on Halloween, and that was hardly the most dangerous enemy I've ever faced."

"No matter." Quirrell snapped his fingers, and ropes bound Nico as well. "A troll is nothing compared to the power of Lord Voldemort."

"And the so-called Dark Lord is nothing compared to me," Nico retorted, shifting his sword to subtly saw through the ropes.

"You have a very overinflated opinion of yourself, boy."

"I'm not the one who styled myself a lord."

"Then why do the ghosts call you that?" Harry challenged.

"I never told them to. They see me for who I truly am. Death and darkness are my domain." Nico looked back at Quirrell. "And you—what is the point of serving a dead wizard?"

Quirrell shook his head. "He is not dead. I met him in my travels around the world. He showed me my own naiveté—that there is no good and evil, only power, and those too weak to seek it…I am weak, I know this, and he has had to be hard on me. He keeps a close watch on me now. He is with me wherever I go."

"He…ohh." At last, Nico understood what he'd been sensing from Quirrell all year. But then why did he get a similar sense from Harry?

"Yes," Quirrell said absently, running his fingers along the mirror. "I don't understand…is the Stone inside the mirror? Should I break it?"

"A terrible punishment awaits those who defy death," Nico warned.

"Silence!" Quirrell hissed. "What does this mirror do? How does it work? Help me, Master!"

And then a second voice emanated from Quirrell, though he did not move his lips. "Use Potter…use Potter…"

Quirrell whirled around to face Harry. He clapped his hands, causing Harry's bindings to fall off. "Come here, Potter. Look in the mirror and tell me what you see."

Harry shakily walked toward the mirror. He stared into it for a few moments, then his eyes widened.

"Well?" Quirrell said impatiently. "What do you see?"

"I see myself shaking hands with Dumbledore. I-I've won the house cup for Gryffindor."

Quirrell cursed. "Get out of the way."

Harry slowly backed away. Meanwhile, Nico succeeded at cutting himself free. He stood up and hefted his sword again.

The second voice spoke again. "He lies…he lies…"

"Potter, come back here! Tell me the truth!"

"Let me speak to him," the other voice suggested. "Face-to-face."

"Master, you are not strong enough!"

"I have strength enough…for this…"

Harry and Nico both watched in horrified fascination as Quirrell unwrapped his turban. He cast it aside, then turned on the spot. Where the back of his head should have been, there was instead a terrible face with red eyes and snakelike slits for nostrils.

"Harry Potter," Voldemort whispered. His gaze drifted to Nico, and his eyes widened slightly. "And Nico di Angelo. Has anyone ever told you how much you look like your grandfather?"

"You serve my grandfather?" Nico demanded, tightly gripping his sword. Had his entire school year been some twisted scheme of Kronos's?

"I serve no one!" Voldemort hissed angrily. "But it was your grandfather who set me on the path to immortality. Him and that girl. Two little Italian children who barely spoke a word of English…but they had power. I see it in you too…you could join me…"

"Two little…oh. OH." Suddenly, Nico understood. Voldemort had met Nico and Bianca before they went into the Lotus Hotel, and now Voldemort had mistaken Nico for his own grandson. But what exactly had happened? And was he really… "Italian?"

"You did not know your own heritage? I can sympathize…I did not discover my greatest ancestor until I came to Hogwarts…"

"I know my own heritage," Nico snarled. "You have made an enemy of my family, and I will never, ever join you."

"Such a shame," Voldemort sighed. "But perhaps you have more sense, Potter…you need not join your parents…all you need to do is give me that Stone in your pocket…"

Harry seemed to come out of a trance. "NEVER!" He turned and ran toward the black flames. Nico stood stock still in confusion, wondering how in Tartarus Harry had gotten the Stone.

"SEIZE HIM!" Voldemort cried. Quirrell sprang forward and grabbed Harry by the wrist. Harry and Quirrell both yelled in pain. Quirrell let go, his hands blistering.

"Seize him! SEIZE HIM!" Voldemort cried again. Quirrell lunged and knocked Harry off his feet, pinning him to the ground and wrapping his hands around Harry's neck.

"Nico…help…" Harry choked out.

But Nico had seen that Quirrell could not hold Harry, and now he spotted something else—the Stone had fallen out of Harry's pocket. He snatched it up. "This is an abomination, and I will not tolerate its existence for a moment longer." He knelt to put it on the ground, then used his sword to slash it in two. The blood-red color drained from the Stone, and it crumbled.

"ARGH!" Voldemort's face peeled away from the back of Quirrell's head, becoming a misty, specter-like form. He charged at Nico. Nico ducked into the shadow of a nearby pillar and shadow-traveled away.

Once Hermione walked through the purple fire, she waited for Nico. However, he did not appear. After about a minute, Hermione grew concerned. "Nico?"

No response.

Hermione walked closer to the flames, but they now felt uncomfortably hot. It seemed that the potion had worn off. "Nico?"

Still nothing.

Reluctantly, Hermione decided to go back to Ron and Neville. Clearly, there was nothing more she could do here.

Ron was gently shaking Neville, trying to rouse him. He frowned when he noticed Hermione. "What happened? Where are Harry and Nico?"

Hermione nervously bit her lip. "There was a trap where you needed to drink one potion to go forward and a different one to go backwards. Harry drank all of the potion to go forward…but Nico hasn't followed me back. I don't know why. How's Neville?"

"Still unconscious. I'd say we should take him to Madam Pomfrey, but how would we get him to her?"

"Well, maybe we could use those brooms from the key room…"

"I'm a decent flyer, but I'm not sure I could safely fly while trying to keep an unconscious Neville on the broom."

"So fly up by yourself, find a teacher and ask for help. I'll wait with Neville."

Ron glanced worriedly at Neville. "You sure?"

"He's my friend too. I'm not going to hurt him."

"Hurt him?" Ron said incredulously. "You may hang out with Nico, but you're too nice for that. Just…are you sure you'll be all right alone?"

"I…er…yeah. Thanks, I think?"

Ron stood up. "I'll be back as soon as I can." He headed into the flying key room.

Hermione sat down next to Neville. And she waited. And waited. At long last, she heard footsteps approach from both directions. Dumbledore emerged from the flying key room while Nico emerged from the troll room, his wand in hand.

"Nico!" Hermione cried, jumping to her feet. "Where have you been?"

"There were still a few drops of that other potion," Nico replied. He looked at Dumbledore. "Quirrell tried to steal the Stone. You-Know-Who was with him—possessing him, or something very similar. Quirrell and Harry got in a fight, and for some reason Quirrell couldn't touch him…" Nico started and blinked. "Quirrell's dead. I'm not sure what happened to Harry or You-Know-Who, I came looking for help."

"I feared as much," Dumbledore said grimly. "And Mr. Longbottom, is he all right?"

"Just knocked out…we hope," Hermione answered.

Dumbledore nodded. "Wait while I fetch Harry, and then we will take Mr. Longbottom to the hospital wing. And…you've been very brave, all of you."

Back in the dormitory, Nico stared at his canopy, pondering the many questions that the night's events had raised. What had he been sensing from Harry all year? How exactly had Voldemort cheated death? What did he mean when he said that Nico and Bianca had set him on the path to immortality? And what was that Cloak that Harry had used?

Finally, he fell asleep. He found himself standing by a pair of freestanding elevator doors somewhere in the Underworld. A dark-skinned man with black wings stood by the doors. Nico had never met him, but he instantly knew who the man was—Thanatos.

"I see you have encountered my old Cloak," Thanatos stated.

"That's what Harry used? Why does he have your old Cloak?"

"A long time ago, three brothers defied me. I offered them each a reward, intending to entrap them. As I expected, the first two brothers requested gifts that quickly led to their own demises. However, the third brother was wiser. He asked for the means to prevent me from finding him. And so I gave him the Cloak. He hid under it for many years, but once he had attained a great age, he shed the Cloak and went with me willingly. For that reason, I have allowed his descendants to keep the Cloak."

"So…Harry is a descendant of that third brother?"

"Yes." Thanatos leaned against the doors. "Harry isn't what you think he is. Voldemort evaded me by splitting his soul multiple times. By the time he tried to kill Harry Potter, his soul was so unstable that it split on its own, and the newly split fragment latched onto Harry. Neither Harry nor Voldemort has any idea. Harry is fully in control of his own actions."

"And…Quirrell? Did something similar happen to him?"

"No. He was possessed by the original piece of Voldemort's soul—the piece I tried and failed to collect the night he killed the Potters. So long as the other soul fragments remain, I cannot touch him."

"So you're asking me to track down the other pieces of his soul?"

"You already want to, do you not? You are a child of my master. Everything about Voldemort disgusts you. You want him to face the judges."

"Yes," Nico admitted. "I do."

Thanatos smiled. "Then I have no need to issue a quest. Consider this nothing more than a friendly chat."

"Lord Thanatos…what did he mean when he said that Bianca and I set him on the path to immortality? Surely we wouldn't have told him to split his soul?"

"I am afraid that is a question to which I do not know the answer. But I am certain that you never intended to set him on that path, else your father would have punished you severely."

Nico shuddered. "He probably would."

Thanatos nodded. "Indeed. Take care, child. I do not imagine your father wishes you to take your final journey any time soon."

Nico woke. He absently stroked Vescia, pondering the night's events. Thanatos had certainly given him a lot to think about.

A/N: You may have noticed that Nico refers to Voldemort as "You-Know-Who". I know that a lot of crossovers have demigods scoff at the idea of being too scared to say his name, but I don't think they'd find it so ridiculous—in the world of gods and monsters, names really do have power.