"Severus," Voldemort said wispily, "you betray me."

"One good turn deserves another," Snape said silkily. "You promised not to murder Lily Potter, and you did."

"She got in my way!" Voldemort spat.

"You gave me your word." Snape glared at him. "If you would have let her live and came back for the boy another time, he would be dead, you would be immortal, and I'd have the woman I really--" At that moment, he realized Lily's son was standing in the room. "Loved," he finished.

"You," Harry said, amazement in his voice. "No. You and my mum?"

Snape shook his head sadly. "No, Harry. Lily and I never had the chance. She was an exceptional woman, your mother-- but much too blinded by James to ever notice me."

"So you thought killing my dad and me would give her a good fresh start, is that it?"

"No," Snape said, "I never wanted it to be that way."

"That's ancient past," Voldemort snarled.

Snape glared back at his master. "No. You didn't stop."

Draco stepped forward. "That's right. You killed my mum."

"And now you want to kill Harry," Snape said, his voice dripping with disdain. He moved in front of him. "And I'm not going to let that happen."

Voldemort's eyes blazed. "I'm going to kill you," he said stonily, "and then I'm going to kill Harry.

"No you can't," Hermione said, her voice strangely clear and confident. "You can't."

"And why is that, you silly little girl?"

Hermione straightened herself. "Because if you kill Professor Snape, you'll just give Harry the same protection as Lily did." She folded her arms. Draco laughed.

Voldemort leered. "I may not be able to kill you," he said to Snape, "but I can cause you pain!"

Snape raised his wand. And as the first jet of light flew through the air, all hell broke loose.

Fenrir Greyback, poised to attack, dove for Ginny. "Hello, pretty..."

"Stupefy!" hollered Harry, and helped her to her feet.

"You are nothing," Snape yelled at Voldemort, "nothing... I will squash you..."

"You are weak!" Voldemort spat at him, as Hermione sent a Patronus into the air, whispered in its ear, and watched it soar away. "No one matches up to my power!"

Ron was holding off Antonin Dolohov. "Incarcerous!" he yelled. "Petrificus totalus!"

"Brilliant!" Hermione approved.

Bellatrix held Luna to the floor. "Try," she was shrieking. "Try!"

Luna laid on the floor, calm, not struggling at all. "Are you right in the head?"

"Expelliarmus!" cried Neville, turning Bellatrix's attention towards him.

"Little Longbottom," she said patronizingly. Holding out her hand, her wand snapped into her palm. "Any gum wrappers in your pockets?"

"How do you know about that?" Neville was livid. "You foul--"

She grinned, hair flying in every direction, eyes popping out of her head. "You're fragile," she said in a wilted voice. "All of you Longbottoms."

Neville mustered every ounce of courage he had, all the hate and scars, every last bit of awful feeling, and glared at Bellatrix. "You don't scare me," he said, calm as Luna. "Stupefy!"

And he blasted her across the room, sending her into the veil-- it was like slow motion as she met Sirius' gaze, and he waved at her as she disappeared.

Meanwhile, Lucius was advancing on Draco. "So," he said crisply. "This is how you repay me. My only heir, turning on the Dark Lord-- making friends with Harry Potter-- throwing our pure wizarding heritage to the dogs by dating a Mudblood!" He indicated Hermione, who was locked in combat with Natalya.

"Father--"

"Don't speak to me," Lucius drawled, drawing his wand. "I have no more use for you. Avada--"

"No!" screamed Hermione, turning from Natalya. She flung out her arm.

But Harry was faster. "Crucio!" he screamed. And a jet of light flew from the tip of his wand, hitting Lucius squarely in the chest.

Hermione looked up, shocked, while Percy kept Natalya from hexing her. "Harry!"

"I'd explain myself," Harry said, "but I made a promise."

Draco caught his eye. "Thanks, mate."

Harry nodded.

At that moment, the rest of the Order of the Phoenix appeared in the room, wands brandished.

"Ah," Eva said, taking a deep breath, "battle." And, with her eyes aglow, she jumped into the fray, shooting a jet of red light at Dolohov.

"Merlin's beard," Avery said in a shaky voice. "It's Wingfield."

Her eyes glittered. "Hello, Avery." And in one swift move, she pulled a silver knife from her robes and stabbed him in the heart, then tossed it to Lupin. "Thought you might want this," she said.

Lupin grasped it by the handle and rushed at Greyback, who had pounced on Luna.

"Remus Lupin," growled Greyback. "Still out for vengeance?"

"It's not only about vengeance," Lupin said, staring into Greyback's feral yellow eyes. "It's about preventing you attacking one more child."

"There's nothing you can do." Greyback licked his lips. "They'll all be turned by night's end-- at least, the survivors." He grinned ferociously.

"That's where you're wrong," Lupin said flatly, and drove the knife into Greyback's chest.

"You're not as strong as you once were!" came Snape's cry. "Dumbledore has weakened you! Harry has weakened you! You will never be the greatest wizard alive!"

"Yes, you, the Half-Blood Prince, who created so many spells, so many potions." Voldemort's eyes flashed. "Sectumsempra!"

Snape fell to the ground, gashes covering his face.

"Professor!" Harry shouted. He wasn't sure how he felt about Snape; but he would rather see him live than Voldemort.

"Harry." Snape seized the front of his robes. "No more secrets. I want you to know that I didn't want Dumbledore dead any more than you. I would have died rather than see him go-- and I offered it. He was like a father to me, Harry. He-- he believed in me when no one else would, gave me a family."

Harry thought briefly of what Hermione and Draco had said. "Then why did you kill him?"

A tear slid down Snape's cheek. "Because he asked me to."

Voldemort glared at Harry, barely aware of Snape. "How weak he is," came his offhand remark, and he stared directly at Harry. "Avada..."

"No," Snape whispered. And he pulled Harry down by the hem of his robes, using every last ounce of strength he had left to take Voldemort's Killing Curse directly in the chest.