Regulus returned back to his own house for the rest of the night, promising Alexandra that he would come back the next day, so they could meet up again.

       Alexandra didn't sleep the entire night and kept awake, going through her plan a hundred times, over and over again. It had to be flawless. It had to work.

      The next day, as she had planned, Alexandra asked Edna to make her Cullen Skink, which was a traditional Scottish food, knowing that Edna would go all the way with Floo Network to provide the best for her, as a small way to make it up to Alexandra for saving her life. This meant that Edna would be away for long hours, leaving the house empty.

As promised, Regulus showed up that evening, looking distressed as he walked into the house, joining Alexandra in the living room.

"I found something," said Alexandra before even greeting him, taking out a thick book from the table before the couch, opening it up to a page she had marked, with four pictures inside it.

"What is this?" Regulus asked curiously, sitting beside her on the couch.

"It's an old history book, about the Hogwarts' founders," she explained, showing him the pictures. "These are the most well-known objects that belonged to the founders, but no one knows where any of them are now; the sword of Godric Gryffindor, the cup of Helga Hufflepuff, the diadem of Rowena Ravenclaw, and this."

She then pointed at the fourth picture, which was a locket exactly like how Kreacher had described it, with a snake carved upon it.

"The locket of Salazar Slytherin," said Regulus in a mutter, staring down at the picture. "This is what the Dark Lord has hidden in the cave. This must be the object he had chosen as his Horcrux."

"Precisely." Alexandra nodded, putting the book aside.

But what caught Regulus off guard was when Alexandra dug into her pocket and took out a locket, somewhat identical to the one in the picture.

"Hang on! Where did you get that? I thought we were using a random locket —"

"I already had a simple locket of my own, so I spent most of last night awake, trying to use as many transfiguration spells I knew on it to make it look like the one in the picture, so we can replace it with the real Slytherin locket," she explained. "The later the Dark Lord finds out that his locket is missing, the more time we have to destroy it and to leave without being suspected."

Regulus nodded, pursing his lips together. He then fished into his cloak's pocket, take out a large glass jar, which contained a dark green liquid inside it.

"This is called the Emerald Potion, or most commonly known as the Drink of Despair. From what Kreacher had described what he had seen in the basin, I guessed that this was the Potion the Dark Lord had used," said Regulus.

      Alexandra frowned. "But where did you get that?"

      "Just bought it. From Borgin and Burkes," he explained. "After we've replaced the lockets, we can pour this potion back into the basin, to make it harder to realize that the real locket is missing."

"So... let's go through the plan one last time, shall we?" said Alexandra after a long pause, avoiding his eyes.

Regulus nodded. "We'll ask Kreacher to take us to the cave. We'll travel across the lake, like he said, and get ourselves to the basin. One of us will drink the potion inside it to be able to empty it, we'll switch the lockets and fill it up with the new potion, and Kreacher will get us out of there."

      "I hope you're not planning on drinking that yourself," said Alexandra, looking at him intently. "It has to be me."

"Why does it have to be you!?" He frowned.

"Because — because I can't bear to see you get hurt!" she tried to reason in frustration.

"And do you expect that I'll be okay to see you suffer?" Regulus retorted, silencing her. "Look... how about we go over the main plan, and then when we get there, we'll decide on the rest. Because chances are that not everything will go as planned."

Alexandra gulped nervously. "You're right... what if things don't go as planned?"

"Then we'll decide on a safe word, so Kreacher will get us out of there if we say that word," Regulus said half-jokingly, grinning.

Alexandra chuckled. "Okay... how about 'red'?"

"Hmm... nah. It's too cliche." He smirked. "How about 'Raven'?"

Alexandra giggled. "Why would you want to have the safe word as my Hogwarts House?"

"No, not your House." He shook his head, now smiling. "Raven as in your hair color... Raven black."

Alexandra couldn't help but smile at those words, and so she reached out to hold his hand in hers softly.

"And you call me 'weirdo'?" she said teasingly, making him laugh.

"That's your curse, Alexandra Starling," he said, smiling. "You make everyone fall in love with you and you turn them just as weird as you."

Alexandra chuckled, moving forward to press her lips against his, bringing him into a kiss. They both wished that they could stop the time, and to keep this moment alive forever. But it was hopeless.

       When Regulus finally pulled away, he took out a parchment in which he had written a short letter last night, handing it to her.

"Go on. Read it. Tell me what you think," he said.

Alexandra looked down at the letter, reading it out loud under her breath,

To the Dark Lord

I know I will be dead long before you read this, but I want you to know that it was I who discovered your secret.

I have stolen the real Horcrux and intend to destroy it as soon as I can. I face death in the hope that when you meet your match, you will be mortal once more.

R.A.B.

"R.A.B?" Alexandra repeated after reading the letter, looking back up at Regulus with a teasing smile. "Trying to take all the credit to yourself, are you?" He laughed.

"That doesn't stand for Regulus Arcturus Black," he said, grinning.

"Oh yeah?" She raised an amused brow at him. "Then what does it stand for?"

"Well... I thought it could stand for Regulus and Alexandra Black."

"But my surname isn't Black," she said, chuckling.

But Regulus only winked at her, saying, "We'll see."

***

Despite their little jokes as hard efforts to brighten the mood, neither of them could truly feel at peace that night. Regulus couldn't remember ever feeling this concerned as he returned back home later on that night, possibly for the last time. He didn't know when he was going to see his parents again, if ever.

But this was way more than his family. This was about the future of the Wizarding world. It was about trying to save the families that the Dark Lord could easily tear apart. It was an attempt to give an end to all the murders, all the tortures, and to save all those innocent victims from their terrible fates.

This had to be done. Voldemort had to be stopped.

That night, after bidding his parents goodnight, Regulus went down to the kitchen instead of going to his bedroom, and went to visit Kreacher in his cupboard, feeling disturbed in his mind.

       Regulus was breathing rapidly, feeling his mouth going dry. So casting a silencing charm around the kitchen, Regulus went by the cupboard and knocked gently, opening its door to reveal Kreacher, curled up inside it.

"Kreacher, I-I need to ask you for a favor," he said kindly, though Kreacher could see the nervousness in his eyes.

"Anything for Master Regulus," said Kreacher, bowing his head so low that his nose nearly touched the kitchen floor.

"I need you to take us to the same cave which the Dark Lord had taken you," said Regulus, holding his breath. "But listen carefully to what I say now... while we're there, you must take orders from me, and me only. Nobody else. This is for the best."

      That's the only way I can get Alexandra out of that cave, without her trying to save my life before hers, he thought to himself.