Marissa only sat, silent, for a long time. Finally she turned to Moon, tears in her eyes and down her face. Her voice was quiet, bitter. "You did this to him."

Moon only stood, her eyes flat. "It was his idea. If he hadn't offered his life, you would have lost yours."

"How could you?" Marissa glared, her hands beginning to shake, "How could you be so cruel? You know I can't live without him! He's my brother!"

Moon kept her voice even. "He asked me to. He said he'd rather see himself die than have to bury you."

"Phineas?" came Isabella's squeaky voice from behind them, and Moon turned to see her with a heavy ceramic bowl in her hands. Seeing what had happened, Isabella dropped it, and it shattered on the floor. "Phineas!" she ignored the fragments of ceramic on the floor around her as she darted to Marissa's side and quickly took Phineas' hand. "No..."

Ferb put a hand on Isabella's shoulder without a word. His mind, too, had frozen shut against all the feelings that were waiting at the gates once it would open back up. Denial, love, hatred, fear, anger - everything pounded at the edges of his mind, demanding to be let in despite the shock that had paralyzed him. Slowly it began to fade, the numb emptiness receding to make way for the full realization of what had happened, that he'd just witnessed his brother die. The gates opened; everything came flooding in all at once, overwhelming his mind and making him a little dizzy. He could see Phineas staring back at him, his eyes empty, dried tears still staining his face, his mouth hanging open slightly, rimmed with a thin line of blood. Without thinking he pulled him up into his arms and cried.

"Quite finished?" Moon asked in an aggravatingly neutral voice, having found a catlike pose on the bed, like a tricky sphinx watching a petty quarrel between two rats.

Isabella just glared. "How could you say that?" she demanded, "Look what you've done! You can't just pretend it's nothing! What kind of heartless monster are you?"

Moon only sat, her feet crossed behind her, her hands keeping her balance as she leaned forward on the edge of the bed. "You wanna see something cool?"

"Don't you get it?" Isabella exclaimed, "You just killed someone! You think you can erase that with some stupid trick you can do? That's not going to happen! You can never make this okay! It's because of you that Phineas is dead! This is your fault! You can never undo this!" she glared at Moon, her eyes full of fury and hurt, but then she just sat back, sobbing.

"Maybe I can," Moon stated simply, as if completely unfazed by Isabella's anger.

"You've done enough already, Moon," Marissa told her, her voice stiff but cracked, "Just leave us alone. Go back to whatever hell you came from."

Moon's eyes shifted to Marissa, still neutral. "I'm serious," was all she said.

"Moon, enough," Isabella scolded, blinking away two enormous tears that had formed in her eyes. "This isn't funny!"

Moon just sat. After a moment she smirked. "I'll bring him back for you," she said, "But you have to keep it a secret."

"What?" Marissa cried, "What kind of sick game is this? Even supposing you could bring Phineas back, there's no way we would keep him hidden away all the time!"

Moon shook her head. "You don't understand. I meant you can't tell anyone he was ever dead."

Marissa could feel her face beginning to turn a dark pink. She glared at Moon, her eyes flaming, and when she spoke her voice was a quiet fury. "I hate you, Moon. You're a sick twisted monster. Whatever game you think you're playing-"

"You better be careful what you say," Moon retorted, impatience creeping into her voice, "I'm the one that can bring your brother back."

Marissa only sat for a moment, but then finally relented, hanging her head and taking a deep breath. "Anything for my brother," she whispered.

"Better. Now if I find out you've told anyone what Im going to tell you, I'll rip your face off. Got it?"

Marissa nodded. "As long as you can bring my brother back."

Moon glanced over at Isabella. "You too."

"Fine," she agreed, "But I still hate you."

Moon shrugged. "Don't care. Goes for you too, Brit. You better swear not to tell."

Ferb only nodded, Phineas' limp body still held tight in his arms.

Moon nodded, satisfied, and then sat back. "Fine," she glanced over at the little black creature that had been sitting in the doorway. "It's called a necrovore. That's what'll be bringing your brother back from the dead."

"But-" Isabella protested.

Moon shot her a look and Isabella fell quiet. "They're supposed to be extinct. They were never really common, but on the rare occasion one was found it was kept for its power, and they often died because of mistreatment."

"What kind of power?" Marissa asked, "It's just a little monster, isn't it?"

"No," Moon shook her head, "And this is where it gets interesting. They eat death. When someone dies they can pull the death out of them and allow them to live a little longer. People would keep them for this, and because of their mistreatment they're nearly extinct. I hadn't thought there were any left, either. Kinda took me off-guard when you told me about it, actually," she smirked.

"So you mean as long as we keep it as a pet we can live forever-?" Isabella began.

"Absolutely not," Moon snapped, her tone suddenly fierce, "That's the reason so many of them were poisoned to death. They can't eat the same death twice. If that happens they get sick, and unless they spit it back up they'll die. But people ignored that. They thought each other's lives were worth more than the necrovore. They killed them off. This is probably the last one. It has to be kept safe, and you can't possibly be trusted to do that."

Isabella just sat, taken aback by Moon's words, and after a minute she nodded meekly. "Okay."

Moon settled, silent, and glanced over at the little necrovore on the floor across the room. It would decide for itself whether it would feed; Moon would only give it the chance.

The creature seemed a little nervous, but nonetheless it approached Phineas' body, sitting by his shoulder and sniffing him over with its crocodile-nose. It hesitated a moment, and Moon gestured for Marissa and Isabella to back away so that it wouldn't feel threatened by them.

Soon as they did, the necrovore relaxed. It hopped up onto Phineas' chest, settling over his ribs like a lion or a wolf pinning its prey, and then clamped both its jaws over his throat. Its six tails sprung out as it tugged back, its four feet planted like a labrador puppy fighting for its toy. The red that came slowly out was not blood - a dark aura, resembling Phineas, being pulled away. The creature tugged harder, soon dragging the aura away from the body. Now satisfied, it tore it up and devoured it, its teeth ripping it apart so that it could swallow the pieces. When it was finished it had grown, easily six inches longer than it had been before, and it returned to Phineas' side, giving him a single lick where Moon had slashed him. Instantly the slash in him was gone, and the creature sat back, its work finished.

There was silence for a long moment, but then suddenly Phineas revived, coughing up little spatters of blood at first and then settling down to catch his breath.

"Phineas?" Isabella squeaked.

Phineas coughed. "What? Am I-? Am I dead...?"

"Phineas, you're fine," Marissa whispered.

"What, I'm-?" Phineas didn't have time to answer before Marissa pulled him into her arms, a minute later joined by Ferb and Isabella. Moon preferred just to sit and watch from her place on the bed, but she gave a tiny smirk nonetheless.

After a moment, Phineas turned to Moon with a grin. "C'mon, get in here."

Moon only shook her head. "I don't hug, remember?"

"But-"

"Not," Moon cocked an eyebrow to accentuate her point.

Phineas only shrugged. "Well, okay. I guess this is it, then. I guess we go home."

"Not yet," Moon told him, "We have to go and kill the monster first."

"Why can't we just let it go into the wilderness?" Phineas asked, "Killing things isn't nice."

"Then you can just sit and watch. How's that?" Moon replied a little irritably. She set her hand on the hilt of her knife and held it there for a moment, as if contemplating, and then nodded to herself and disappeared down the stairs.

"Moon!" Phineas called after her, trotting down the stairs, "Hold on a minute."

Moon turned, her arms crossed, and gave him a skeptical look. She didn't say a word, but it was clear to Phineas that her mind was made up. She wasn't going to spare the demon, no matter what he said.

So he didn't say anything. He just turned and went back upstairs. A minute later he returned, with Ferb and Marissa and Isabella close behind him, and stood for a moment at the top of the stairs before following Moon down to the door to the basement.

"Hey," Ferb told her quietly, taking one of her hands and looking up into her eyes. "Thanks."

Moon regarded him in silence for a moment, but then nodded. She pulled her hand slowly out of his grip, turning back to the door and heading into the basement.

All they saw was the brief flash of teeth before Bellidor attacked.