"You go first," Dipper prompted.

"No, you go first, I talk too much anyways." Mabel was trying to have what would be one of the most important conversations of their lives, but she tried to keep it light like she always did.

Dipper appreciated his sister's positive attitude in face of something scary. "I never thought you talked too much."

"That's because you're so young and naïve," Mabel kidded as she tapped his hand.

"Hey, I'm only two minutes younger than you!"

"And what a difference two minutes makes, my dear little brother!"

Dipper laughed. "Remember how I used to always ask Mom when I would be older than you?"

"Yeah, and she explained that even during leap years I would always be older!"

"She always said I was worth the wait though…" Dipper said wistfully.

"I still miss them."

"I know. Me too. I wonder what it would be like to see them again?" That thought had crossed Dipper's mind many times since his diagnosis.

"Too bad you aren't going to find out for a long, long time, cause my super kidney is gonna save your life tomorrow!"

Dipper's heart both swelled and broke at the same time. He was so jealous of how optimistic Mabel could be.

"Mabel…it might not work." Dipper took no pleasure in being a "Devin Downer" as Mabel called him, but if this had the potential to be one of his last conversations with Mabel, he couldn't leave anything unsaid.

"Don't talk like that Dipper!" Mabel pleaded as she grabbed his hands.

"Mabel…" Dipper gently brushed the hair from her face. He wasn't trying to scare or upset her. She had worked so hard staying happy and upbeat before the surgery. He felt like he was ruining it.

"I would never forgive myself if something happened to you," she whispered.

"I would never forgive myself if something happened to you, Mabel. You don't have to do this. You can opt out right now. Get your spot back on the squad-"

"No, Dipper, I want to do this for you more than anything. Just once, I want to feel like I'm the type of sister that deserves a brother like you."

Dipper looked at her confused. She was the one giving him her kidney. She was the hero of the situation and yet, she was heaping praise onto him.

"You've always been the best brother in the world. You've been there for me through some really scary stuff. You have spent your whole life putting me first, and this is my chance to put you first for a change. It's my chance to sacrifice for you. My chance to show how much I love you, bro-bro, cause I do. You are the best brother anyone could ask for, and I'm not going to lose you!"

Dipper pulled his sister into a tight embrace. He didn't care that his whole body was aching. He wanted to hold his sister and never let her go. "You are the best sister I could ever have. I'm proud that I am going to have part of you inside of me."

The words felt funny but amazing to say. Tomorrow, his sister was going to give a part of herself to him. It was a gift that Dipper wouldn't be able to repay if they lived for a thousand years.

"After tomorrow, you and I will be even closer than regular twins. We will be super twins!" Mabel declared.

Dipper smiled. "We're better than super twins, we're the mystery twins, remember?"

"How could I forget?" Mabel said as the two did their handshake.

"Mabel, will you promise me something?"

"Anything, bro-bro."

"Promise me that no matter what happens tomorrow, that…that you won't blame yourself if I…" Dipper couldn't make the words. He was afraid of those words just like any kid would be. He wasn't particularly religious, but he had spent a lot of time praying lately. Some nights, he would stare up at the ceiling and talk to his parents as if they were still there. Even though he never got a verbal answer, he still found comfort in it. He made peace with the fact that he may not survive tomorrow. He just wanted to give Mabel the same peace.

"Shh!" Mabel was clearly not hearing it right now. Dipper didn't expect her to. He wanted to wake up from the surgery tomorrow for Mabel's sake more than his own at this point.

"I'll promise…if you'll promise you won't blame yourself if anything happens to me," said Mabel.

Dipper swallowed the lump in his throat. He knew he couldn't make that promise. He knew if Mabel got hurt, he'd never forgive himself. But if he wanted her to do it, the least he could do was reciprocate. "I promise."

"Okay, then I promise too," Mabel said as she hugged him tight again.

Dipper decided to change the subject. "So…Pacifica has come by every day this week. Do you think it means something, Miss Matchmaker?"

Mabel's eyes lit up as she launched into a screed about how much Pacifica was crushing on him. One of Dipper's favorite things about Mabel was her passion. When his sister believed in something, she believed it heart and soul. Dipper admired that about her. Knowing that she believed heart and soul the surgery would work helped convince him the same.