Severus did not panic. He cast Protego, raising a transparent dome that caught the knockback jinx, and at the same time he flicked a disarming spell at her. The woman mirrored him perfectly, blocked, and stepped aside with sharp speed. She looked ready to strike again, but Regulus moved in front of Severus.
"Cousin, stop it! He helped me!"
The woman shot Regulus a displeased look, tucked a strand of dark hair behind her ear, and then glanced at Severus with suspicion. Up close she was undeniably attractive in the sharp, aristocratic way of the Blacks, and just as dangerous, like a knife that enjoyed being used.
"Grandmother told you a hundred times not to go out alone, and not to associate with any mudbloods."
"I needed to pick something up," Regulus said with a tired sigh. "I did not expect a trap, or that they would try to kidnap me. Sorry. I wanted to handle it myself and not bother you or Grandmother."
"I see," Bellatrix said irritably, eyes still on Severus. "I am not thanking you. Just tell me what you want."
Severus had an idea a moment ago, but after she appeared, and after the marks he had felt on her arm, he abandoned the thought of using the Blacks to find the Parselmouth.
"I think I will keep it to myself."
"Speak," Bellatrix said, voice sharpening. "I do not want anyone knowing the Blacks owe something to a half-blood."
"Oh, very well." Severus walked past Regulus and stopped right in front of her. He smiled and let his gaze travel over her face, over the aristocratic pallor, the full scarlet lips, the thick lashes, the dark eyes narrowed as she jabbed her wand into his chest and restrained herself only because he had saved her cousin.
"Then I want one thing from Miss Black," Severus said softly. "One kiss. Is that a fair price for saving Regulus?"
"You want to die?" Bellatrix did not blink. Sparks danced in her eyes, promising that if he asked for anything else like that, his body would be found in this alley.
"And here I thought the Blacks never went back on their word."
Her eye twitched, and the tip of her wand flared brighter.
Regulus wiped cold sweat from his forehead. The tension in the air was thick enough to choke on, and he could almost hear his own heartbeat. He knew better than anyone how much Bellatrix hated non-pure-blood wizards, and her temper, and her slight sadism. The fact that she had not already used her favorite curse, Crucio, was a miracle, and that miracle was hanging by a thread.
"You do not want to rethink it?" Bellatrix asked, voice flat and murderous.
"Of course not. It is rare to meet a girl as attractive as you."
Disgust flashed across her face, and the wandlight brightened again.
"I am giving you one last chance. Ask for something else."
"Fine, then I want nothing," Severus said, waving a hand. "I should not have expected anything else from pure-blood wizards. Empty talkers. All you can do is stab someone in the back."
He walked past the frozen Bellatrix toward the alley exit.
"You." Bellatrix hissed. "How dare you insult pure-blood wizards, you filthy mudblood. I will kill you right now!"
She pointed her wand at his back, but she could not bring herself to fire. His last words still rang in her ears, and if she struck him from behind, she would prove him right.
Grinding her teeth, she strode after him, grabbed his shirt, and slammed him into the wall. The wandtip pressed to his chest as she seized his collar and bit down on his lips.
How easy it is to pull her strings. Severus thought, smiling inwardly. But this will not do.
He slid one hand to her waist, the other to the back of her head, spun her around, and pinned her to the brick wall with his body.
Bellatrix froze for a heartbeat, shocked by the reversal, and then anger surged, but a second shock followed when Severus's tongue pushed into her mouth with bold, practiced control.
It did not last long. She snapped back to herself, bit his tongue, and he pulled away, letting her wrench free.
"Delicious," Severus said, licking his lips. "Have you had strawberry cake before?"
A faint blush rose on her pale face, and the thirst for blood in her eyes turned feral.
"I WILL TORTURE YOU, YOU DAMN BASTARD! CRUCIO!"
Severus dodged.
"CRUCIO!"
He dodged again. A black needle slipped from his pocket, unfolded into a cube in midair, and snapped into place.
"CRUCIO!"
This time Severus did not bother to dodge. He kept backing away, and the curse never reached him. The cube flared with an azure glow, swallowing the beam and shielding him as he retreated.
"CRUCIO."
"COUSIN, ENOUGH!" Regulus grabbed her wrist as people began gathering at the alley entrance. Severus turned once, blew Bellatrix a kiss, and disappeared around the corner.
"Let me go! I will kill him!"
"He is already gone," Regulus said desperately. "And if you keep casting that, you will draw attention!"
Bellatrix tore her hand free, stared in the direction Severus had vanished, then turned her cold gaze on Regulus.
"If you tell anyone about this, I will kill you."
"O-of course." Regulus nodded with a strained smile, silently cursing Severus for leaving him alone with an enraged Bellatrix.
Severus had to fight down laughter as he left Diagon Alley.
You are savage, you crazy woman. If Regulus had not been there, you would have killed me the second I opened my mouth, but.
He licked his lips and glanced toward the unremarkable bar. Still, it was pleasant. I have not been interested in women in a long time.
He nicked his index finger and drew a diamond shape on his palm with blood. After a few seconds it flared and shrank into a small tattoo, two centimeters by two. He fed it a thread of magic, and an image of Bellatrix rose in his mind, currently destroying her room in a rage.
Taming a tigress like that will be difficult. And the influence of Crucio is not good for the mind. It has been used on her more than once. A simple restorative potion will not be enough, but I will think about that later. For now, at least I can watch what is happening in the country firsthand.
The spell Severus used was blood magic. Bellatrix had already bitten his lip hard enough to taste blood, and that single drop was all he needed. The principle was simple: if the target consumed even a drop of the caster's blood, the caster could form a seal inside the target and observe them, and also sense their condition, physical and mental.
Well, time to go home. I need to start preparing the potion.
He looked toward the road and, with obvious reluctance, pulled out his wand and waved.
A moment later a purple bus appeared out of thin air. The door swung open, and the grinning driver leaned out.
"Glad you chose us again. Hot chocolate? A hot water bottle? A toothbrush?" The old man's cheerfulness made Severus twitch.
"I will pass."
"As you wish."
Only a few minutes later, the bus braked hard, tossing him forward again, as if it took personal pleasure in reminding passengers that gravity was optional.