DISCLAIMER: I don't own any of these wonderful characters, I'm just borrowing them from Queen Rowling.
I read a story where Voldemort killed Narcissa for lying, and it got me wondering why, when the fight broke out again, didn't he immediately go for her? So here's a little snippet of what I think could/might have happened.
Narcissa stood rigid as Voldemort strode back and forth before them, red eyes flashing maliciously as he proclaimed the death of Harry Potter. Next to her, Lucius was almost as immobile as his wife, taking her hand with such strength that she would be surprised to withdraw it and find her fingers intact. Part of her ached to tell him, to reassure him that all hope wasn't lost, that Potter was very much alive. But he couldn't know; it was her secret, her burden to bear should Potter fail a second time. Iron bands squeezed around Narcissa's chest suddenly as she realized the position she was now in. What may befall her was immaterial, but Voldemort could, and most likely would, decide to punish Lucius or Draco before killing her. The very thought of it made her want to vomit.
Suddenly there was a loud roar and all hell broke loose. Lucius grabbed Narcissa's arm and hauled her to the side of the Great Hall as Death Eaters surged forward around them. Out of the corner of her eye Narcissa saw Potter leap to his feet, and a split second later Voldemort's high-pitched scream rent the air. A block of ice slid into her belly: He knows.
"You lied." Lucius' hand tightened painfully on Narcissa's arm, and when she looked at him his blue eyes were twin suns of disbelief and fear. "You lied to the Dark Lord?"
"For Draco, yes." Sensing he was about to yell, Narcissa snapped, "If you want to lecture me, Lucius, save your breath. I did what I had to for our son, and if that reason isn't good enough for you, get the hell out of my sight." Ripping herself free of his grasp, she turned and began to run through the chaos and debris, crying Draco's name as loud as she could.
"Mother?" Draco's voice flooded her like sunshine after a rain. Narcissa spun around, and suddenly he was in her arms, hugging her so tight she swore she felt a rib crack. Not that it mattered, of course. "What are you doing here? I—"
"Looking for you," she interrupted, pressing her lips against his cheek. "Now come, we must leave."
"Where's Father?" Draco took her hand and together they began to run, Narcissa making sure to stay between him and the fray.
"He'll catch up to us," she mumbled, suddenly feeling like a reckless fool. They shouldn't have split up; there was a good chance he wouldn't find them, or that someone had already—
No. NO. Lucius would be fine. He would be back where Narcissa had left him, surely; perhaps he had picked up a wand from a fallen soldier…
"AVADA KEDAVRA!" A shriek split the air, and instinctively Narcissa shoved Draco down before ducking herself, barely missing the jet of green soaring millimeters from her head. Crouching to shield her son as best she could, Narcissa looked up and instantly her eyes were drawn to the fury-filled, blood-red ones of Voldemort halfway across the Hall. Panic flooded through her, venomous and paralyzing, but as Draco tugged away and tried to step in front of her she was sharply brought out of her terror. "NO, Draco, run!"
Before Draco could respond, however, a third figure moved between the two and Voldemort. Narcissa's breath almost literally stopped as Lucius faced his former master, even more unyielding than he had been just moments ago in the calm between the two battles. "Go, Narcissa," he said calmly. "I'll keep him at bay for a moment."
"Lucius, no, no—I lied, it wasn't you—please—" For the first time in her life, Narcissa Malfoy nee Black was begging. As if watching someone else's life she saw Voldemort raised his wand, saw his lipless mouth curl around the words. "Lucius, please!"
He turned—he actually turned away from his own death to face her and smiled. It was the smile that had only been for her since the day they met, the smile she would die for, the one she hadn't seen since the return of Voldemort almost three years ago. "I won't allow my own weakness and cowardice to affect you anymore," he said softly. "I have failed you as a husband, Narcissa—and you, Draco, as a father. Let me attempt to make amends."
"Father!" Draco screamed, and a flash of green seemed to fill the whole Hall. Narcissa heard a woman screaming too and took a second to realize it's her, because her world was about to fall, and surely Draco would die too because of her—
"PROTEGO!" Harry roared, a Shield Charm stopping Voldemort's curse in its tracks. The Dark Lord whipped around, Malfoy family forgotten as his prey finally revealed itself. He hissed in cold triumph, and with a horrible sinking in her gut Narcissa fancied that she could already taste her salt-iron blood as she thrashed in the throes of a Cruciatus Curse.
"I can't believe how lucky we are." Narcissa Malfoy pushed herself closer to Lucius, pressing her face into his chest. "When I think about it now, it seems…almost unreal, how close we came."
"I know." He spoke quietly, trying to hide the pain and fear that was still there even after almost six months. Lucius' arms tightened around his wife. "But I think we have you in large part to thank, love. If you hadn't saved Potter, who knows where we'd be now. You were brave. My brave Cissa." He gently rested his cheek against her hair.
"No." Narcissa shook her head. "That wasn't bravery. It…I had to find Draco. I had to. If that meant helping the boy, then so be it." She shivered slightly. "It was even worth losing Bella…"
Lucius said nothing, simply brushing his lips against her neck. He had never quite understood the relationship between the Black sisters, but it was clear over the years that Narcissa's love for them had not waned; and yes, that included Andromeda. It had been extremely hard for her right after the war, Bellatrix's demise still fresh and Andromeda wanting nothing to do with her after she learned of Narcissa's presence at her daughter's death. It was, he thought almost wryly, material for a romance novel.
Narcissa sighed and seemed to give in, her body relaxing against her husband's. "I'm sorry. I shouldn't be thinking about this. But when I think of how close we came to losing Draco—how close I was to losing you—" Her throat closed suddenly, leaving her unable to speak.
"Shh." Lucius kissed her. "It's all right. We're both fine. Nothing can hurt us now, do you hear me?" He pulled Narcissa even closer, stroking her hair, the slight tremble of his voice the only indicator that he, too, had had this thought and struggled with it still. After a long pause he said, almost too softly to be heard, "You are the only reason I didn't die in Azkaban."
Narcissa's vision blurred as she pulled back and kissed him hard, refusing to allow herself to dwell on that possibility. "I love you so much."
"I love you too."
And for once, the words weren't tinged with fear because now there was forever and a day to say them.