Vault 615
Copyright© 2026 by Carlos Santiago
Chapter 3: An Imperfect Design
Fan Fiction Sex Story: Chapter 3: An Imperfect Design - A special Vault was constructed to help humanity survive the end of the world, but the citizenry of Vault 615 discover there is much more to discover than meets the eye.
Caution: This Fan Fiction Sex Story contains strong sexual content, including Ma/Fa Blackmail Coercion Consensual Drunk/Drugged Fan Fiction Science Fiction Paranormal Cheating Cuckold Cream Pie Exhibitionism Pregnancy Squirting Tit-Fucking BBW Big Breasts Body Modification Hairy Size Small Breasts Geeks Politics
“A nuclear event would be a tragedy ... but also, an opportunity.”
— Barb Howard (as portrayed by Frances Turner), Fallout, Season 1, Episode 8: “The Beginning.” Originally released April 10, 2024, on Amazon Prime Video. Written by Gursimran Sandhu. Directed by Wayne Yip. Series created by Geneva Robertson-Dworet and Graham Wagner, based on the Fallout franchise by Bethesda Softworks. Produced by Kilter Films and Amazon Studios. © 2024 Amazon Content Services LLC. All rights reserved.
She woke up to find her husband gone. Kathryn almost freaked out until she recalled where she was.
While living in a vault was not ideal, she knew there was nothing to do. She could be a homemaker and a sweetheart, but there was no mess or complications of the house that she needed to fix.
When she arrived in the kitchen-dining room, she found a note from Keith saying: “Off to do Vault responsibilities; see you later tonight.”
She had no clue that the fuck that meant, so that left her to wonder what she should do to fill her day. When she looked outside, one of the women was walking back to the auditorium, and Kathryn spoke up.
“Where are you going?”
“To the orientations,” the woman said.
“Why?”
“There’s nothing else to do.”
Kathryn shrugged, seeing the reasoning behind the decision, and she went down to the auditorium.
There were more people than there were the other day. Looking over, she saw a big clock on the wall with the hour minutes and seconds of the day. It was 10:17 AM and 32 seconds.
When she looked over, there was that man again. Only in this moment, she recognized that he was a janitor.
A woman came onto the wall, rather than the man from the other day.
She said her name was Sabrina.
Kathryn was only barely listening. She saw some men were coming together to try and open the Vault door. Only, unlike the designs for other Vaults, there was no key card or terminal.
Even still, as she saw that, she noticed her husband was in the distance with a Mister Handy and some pretty looking scientist.
Kathryn was transported back to her middle class life where she was part of a Rotary Club. She recalled her nice house, two daughters, two cars, and cushy life.
She also recalled how when her husband, Caleb Keith Walker, had it in him to sleep around. He liked playing the big man at times despite not having the largest member. She recalled how he would strut and have his way with some people.
She recalled how once upon a time, he had used Kathryn as leverage to try and seduce a businessman into a position where he would look bad, and then after, he blackmailed him to sleep with his wife.
The only upside was Keith didn’t get that woman pregnant. At least, Kathryn prayed he didn’t.
Shaking her head, she thought that was unfair. Before the bombs fell, he had recommitted himself to their family. Surely, he would not make the same mistakes he did before the end of the world.
Kathryn did not know why, but these thoughts had her wandering rather than listening to Sabrina’s discussion.
“We truly are sorry for doing this to you. This Vault is a secret from most of Vault-Tec, a failsafe if you will, to safeguard humanity. In here, the experts will find some experimental equipment as well as unusually advanced material. For the most part, it should be understandable for those of you who will be using it, but there were some pieces that were so new, we cataloged and shipped it here. We are sorry for that too. Take your time.”
Those words never reached Kathryn’s ears. She found herself moving out of the way of this person and that. A Mister Handy even floated nearby, escorting her off to the side.
And then, funnily enough, she found herself next to the man in the janitorial denim outfit rather than a Vault jumpsuit.
She realized that he had noticed her, but he did not take his full attention off of the screen and Sabrina.
That was shocking for Kathryn. Most men could not keep their eyes off of her. While she did not need male validation, nor did she crave their attention, she found his ability to almost ignore her to be insulting.
It would be bad manner for her to say such a thing, but since Sabrina’s film had run its course, Kathryn thought it best to talk to him.
She did not want to say ‘Hello’ or something blasé. Intellect and good family breeding and societal norms were to be expected of her. To fail in that was the height (or depth) of failure in her eyes.
“With everything going on, why aren’t you trying to get out?” she asked.
She tried to hide her nervousness, but when the man barely moved and did not turn his head to speak to her, she felt insulted.
“No point,” the janitor replied.
He was about six feet, looked to be in shape, but the cleaning uniform was making it impossible for her to be sure if he had muscle or was just slim. He was leaning on a sweeping broom.
“I used to work for Vault-Tec. Nothing special,” he added with a shrug. “I was in robot repair, but those doors ... you can’t force them open. Only that Overseer that lady was talking about or ... that vote I think she said. Only that will open it.”
Kathryn laughed. How did this one man sound more knowledgeable than she ever could in this situation, she wondered. Neither her nor her husband knew that, and her neighbor seemed just as lost as she did.
She thought of Keith. He did not know anything in this new environment, but then, she understood he was likely trying to figure everything out. That was when that young thing near him and the Mister Handy flashed before her mind. She tried not to think about that; instead, she focused on the group of men at the Vault door.
“That won’t stop men like my husband.”
“Caleb, right?” the janitor asked.
“Oh you know him?” she asked.
The man froze for a moment as if he had been caught. He hesitated for some reason. Kathryn could not interpret why, but she looked him over curiously.
“I saw him meet with a big wig at Vault-Tec. You know ... before the end of everything.”
“Oh,” Kathryn said, mouth agape.
“I am sorry,” she went on. “We didn’t pay attention to you before...”
He shook his head.
“Why should you? I am sure you and your family made plenty of money while I was a working stiff,” he said with a winning smile.
She saw how happy he actually seemed, and she realized that before all of this, he was a nobody, and she had been somebody, and she had ignored him.
Now, the roles were slightly reversed. He seemed to know what was going on while she and her husband had not a single clue as to what was going on.
“Kathryn,” she said, extending her hand. “Kathryn Walker.”
“Leo,” the man said. “Leonardo Garcia.”
“Is Leo how you like to be called?” she asked respectfully.
He shrugged.
“Everyone’s called me Leo since elementary school. It sort of stuck.”
She smiled.
“Leo it is. Most people call me Kathryn. My friends call me Katie.”
“Are we friends already?” Leo asked with a mischievously boyish smile.
“I think I might need some friends who actually know what’s going on,” she said with a laugh.
He joined her in the joviality, but then she turned faux-suspious.
“But how is it you know what’s going on down here?” she asked.
He kept laughing.
“I woke up before you,” he said.
“What?”
He pointed to the new people who were not in the jumpsuits and the ones that were.
“They woke us up in batches. Some of the laborers and scientists were woken up in the first batch. I think we were the first batch anyway,” he went on. “Unlike your orientation, mine included a room number and my job.”
“Oh?” Kathryn asked, curiously. “What’s your job?”
He beamed at the question.
“You’re looking at the head robot maintenance repairman!” Leo said with a grin. “Though, I think I am the only repairman.”
He pulled out a card that said: Leonardo Garcia, Vault 615 Head Robot Repairman; Adjutant Janitorial Staff.
“What? How’s that fair? There’s like a billion Mister Handys about,” she cried.
“They mostly repair themselves,” he said. “I am a redundancy. I help fix the robots that aren’t repairable by one another. I think those hoydy-toydy scientists just wanted to make sure everything from the Water Chips to the G.E.C.K.s and smaller parts are in working order. On the upside, I have some Mister Handys helping me from time to time.”
Kathryn could not help but be impressed. She marveled at how at ease this person felt.
“But your card also says ‘Adjutant Janitorial Staff’, doesn’t it?”
He nodded.
“Yeah. I am supposed to help the janitors if there are bigger messes, but I think they have their own crew. Again,” he said with a shrug. “Redundancy.”
“You don’t seem all that upset about it,” she noticed.
She let out a snort of a scoff.
“Of course I don’t,” he said. “Work keeps one busy.”
“And that’s a good thing?” she inquired.
Leo paused, looking at her strangely. Kathryn wondered if he was working something out.
Then he snapped his fingers and nodded.
“I’m sure you’ve heard the phrase, ‘Idle hands are the Devil’s workshop’?”