So this is something I've had in my mind for a while ever since I played Bioshock Infinite. It's my own interpretation of the ending of Infinite. The whole thing is a big mind screw that lends itself to different theories, and this one is my own version of events as I prefer.
This will require knowing the story of Infinite and Burial at Sea. It picks up at the end of the main game but Burial at Sea is referenced. Definitely do not read this before playing the game because it really won't make any sense. It picks up right at the end of the game.
Booker stood confused in the water surrounded by the different Elizabeths. His head was swimming with all the things that had been thrown at him.
"What name shall you take my son?" the preacher asked.
"He's Zachary Comstock," an Elizabeth from the right proclaimed as she grabbed his right arm.
"He's Booker DeWitt," another Elizabeth said as she grabbed his left arm.
"No…" Booker mumbled. "I'm both." The realization hit him. Comstock wasn't just some crazed loon. He was another version of him. All these different universes, with so many similarities and differences to the one he lived in. The Comstocks they saw across these timelines were the Bookers from those worlds.
The Elizabeths pushed him into the water and Booker struggled to breathe. Air escaped from his mouth and he felt his view fade.
The world started to shrink, the details fading. Each Elizabeth disappeared one by one.
Booker fell to his knees, his nose bleeding. He suddenly felt he could breathe again. He was in front of the door he just went through. Somehow.
"I'm sorry Booker." Elizabeth said. She got down on her knees and put a hand on Booker's shoulder.
"What was that?" Booker gasped.
"A pocket world. A reflection of your past that I created," Elizabeth explained, not helping Booker's understanding of the situation.
"And those other Elizabeths?"
"Echoes of me from various universes saying what I was trying to tell you through their own words. I'm still getting used to having my full powers so it ended up being a bit… confusing," Elizabeth explained, again not helping Booker's understanding of the situation. Booker reflected on what he just realized. He was Comstock. He did all that. He took Anna from himself.
"Anna… I'm so sorry…" was all Booker could sputter out. Elizabeth rested her head on her father's shoulder and hugged him.
"I know Booker."
"All that pain. I caused it for myself."
"It wasn't you. Not in the literal sense at least." Elizabeth released her hug and wiped the blood from her father's nose with her sleeve. Booker refused to look her in the eye.
"But I gave you up. I can't forgive myself," Booker said.
"Booker I've seen your past. I know what you did. You're not that man now." Elizabeth turned Booker's face so he looked at her, his eyes overflowing with guilt. "You're my father. We couldn't be together before but we can be now."
Booker held Elizabeth's right hand. The one she reached out with as a baby. He rubbed his thumb over the thimble covering her pinky. He wanted nothing more than to forget everything and just care for his daughter.
"Booker I saw something when I peered into those worlds. I saw infinite Comstocks… an infinite number of you that become Comstock… that do horrible things… and…"
"What are you saying?" Booker asked. Elizabeth looked away as a tear fell down her face.
"I almost killed you," she hung her head in shame. "There was a part of me who wanted nothing more than to see you dead."
Booker was shocked.
"I…" Booker tried to start, but Elizabeth cut him off as she raised her head back up.
"But I saw something else. I saw a vision of me if I let myself become that. I hunted Comstocks across timelines, killing them with no regard to if they were actual monsters. I had no remorse until the consequences of my actions caught up with me. I died miserable in Rapture, with the only company I had in my dying moments being a little girl I tried to take care of and hallucination of you. The only solace I had was knowing that a man would come to Rapture and finish things, save the girl. It showed me…"
Elizabeth held Booker's hand tight but didn't continue.
"Showed you what?" Booker asked.
"That I need you Booker. I can see into the vast sea of worlds where infinite worlds with infinite differences and infinite similarities are laid out like books to read. It's not something people are meant to have flood their minds. It drove the other me insane. I don't want that. I don't want to become that. I realize that you ground me. You give me a real connection to the world to keep my mind from being torn apart."
"So this is why you didn't want me to go through with killing Comstock before he was born."
"I didn't know how to tell you the truth. That Comstock was just some alternate version of you. You were set on killing him before he was born. By doing that it means you die. The only way to prevent any Comstocks from existing is to kill all the Bookers. But I wouldn't kill every Comstock in existence if it meant losing you."
Elizabeth hugged her father. The weary man put his arms around his daughter.
The Lutece twins suddenly appeared.
"We should also offer an apology," Rosalind said.
"We had our own role to play in this," Robert continued.
"Both before and after," Rosalind added.
Booker and Elizabeth pulled from their hug to look at the Luteces. Booker and Elizabeth stood up.
"What are you doing here?" Booker asked.
"To be honest a better question is what are any of us doing here in the first place," Rosalind countered.
"Enough riddles. Enough messing around. Please just get to the damn point already. I'm tired," Booker moaned. Rosalind and Robert looked at each other before turning their gaze back to the father and daughter duo.
"Very well," Robert said.
"We have tried many times to save Miss Comstock-"
"Miss DeWitt," Robert corrected his sister.
"Miss DeWitt from Comstock. We tried many times to get a the corresponding Booker to rescue his Elizabeth-"
"Anna," Robert corrected his sister again.
"Shut it," she snapped. Robert shrugged. "We tried many times to save those Elizabeths from the jail we made possible. It's how we ended up with our current predicament."
"With our ability to move through space at will we thought it would make things easier," Robert said.
"It did not."
"If anything it made things far more complicated. No matter how many times we tried to save Elizabeths and reunite them with their Bookers something always went wrong."
"Too many variables," Rosalind commented.
"Always heads and never tails."
"But what I saw…" Elizabeth said. "You two were there. You talked to Daisy Fitzroy and manipulated her."
"We did some things that were… unethical. For the greater good of course," Rosalind justified herself.
"To be fair that Daisy wasn't the one of the Daisys you encountered. We just needed that one in particular to match the scenario you went through," Robert explained. "Unlike most Daisy Fitzroys we encountered she wasn't as willing to threaten you like that."
"We had to control the variables. Create a series of events that would reliably produce the exact outcome we needed."
"We couldn't just convince an Elizabeth to not murder Booker. No matter how many times we tried it never worked."
"We had to make an example of one Elizabeth."
"One sacrifice to save millions."
"That was an Elizabeth who succeeded. She escaped Columbia, her mind became flooded with overwhelming knowledge of the universe."
"And she killed Booker," Robert said. "Thinking she was ridding us of the evils of Comstock."
"But it didn't stop there. It continued across different universes. She became a serial killer."
"When all outcomes are heads…"
"One must make tails happen," Rosalind finished.
"You orchestrated her death," Elizabeth accused them. "That Elizabeth who died in Rapture died because you made it happen."
"You're not wrong," Rosalind responded.
"But it's certainly not the whole story," Robert finished. "When I convinced my sister to go on this quest of ours-"
"It was an ultimatum brother," Rosalind quipped.
"Hush," Robert responded. "When we started this we knew it was not going to be easy. But trying hundreds of times to write the wrongs we did required us to sometimes do things that are… questionable. Here." Robert pulled a handkerchief from his suit pocket and gave it to Booker. "Your nose is still bleeding."
"Oh, thanks," Booker said as he took it and wiped his nose.
"You have my sympathy Mr. DeWitt. I know what it's like to be dragged into another world and bleed excessively."
"Excessive is a bit of an understatement given I had to give you a blood transfusion for you to even survive," Rosalind said.
"And I thank you for that."
"That Elizabeth needed to end up in the exact situation that we required, which necessitated subtly siphoning her power," Rosalind continued. "All variables needed to be controlled."
"You are free to think our actions are cruel and heartless, but they are the reason you two are standing here," Robert finished.
Booker and Elizabeth didn't have much to say about that. There was a long and uncomfortable pause.
"So what now?" Booker finally spoke up.
"You're free to do what you want Mr. DeWitt," Robert responded.
"We still have work to do," Rosalind followed. "But we will check in from time to time."
"And don't worry about telling us where you are. We'll always find you."
"That doesn't make me feel better," Booker lamented.
"We don't mean that in a sinister way," Rosalind responded.
"At least I don't," Robert said, getting a glare from Rosalind.
"Brother I have only noble intentions."
"Noble intentions to investigate this Booker and Elizabeth because they survived?"
"We must watch over them! They are the only ones who survived. So far at least."
"Don't forget the fact that we still have other Bookers and Elizabeths we need to assist."
"Of course we'll still do that brother. I have no intention of stopping now."
"Well I would certainly hope you wouldn't stop at one victory."
The twins kept bickering on and on seeming to forget that Booker and Elizabeth were even there. Elizabeth turned to Booker.
"Booker… let's go to Paris."
This has been sitting on my computer unfinished for a while so I decided to pick it back up and finish it out. I never found myself really satisfied with how Infinite and Burial at Sea ended. I suppose much of it was meant to leave you thinking about things but I like having a more concise wrap up to a story like how Bioshock 1 and 2 had (and even Minerva's Den). This whole story completely recontextualizes Burial at Sea and what the story is about but I much prefer this interpretation. Anyone is free to disagree, I just personally like this more. Plus getting more concise explanations for the actions of the Lutece Twins is something I really wanted so I wrote that into this story. And ultimately I want Booker and Elizabeth to go to Paris.