After The Vault Dweller returned with Madison Li & some other people after they escaped an Enclave-Occupied Jefferson Memorial, where Project Purity was being operated at, Kai, Felicity, Leela & BOS Steven are now seen having shocked & angered faces after the Vault Dweller telling them that his dad, the man who was at Project Purity, died by Colonel Autumn of the Enclave, who also died as well due to poison gas being released

Felicity had that shadowy eye anime expression, showing that she's upset & angry as she bawled up her fists tightly

Steven: I just.... I can't believe that happened.

Leela was fuming in anger while having some tears forming, but tried her best to calm down and not cause a scene while Kai was balling his fists up as they made metal creaking sounds, since he is wearing his power armor after all

Elder Lyons stared at them and the Vault Dweller with stern eyes

Elder Lyons: all of you, follow me.

he said as he gestured the group & the vault dweller to follow him as he went through the doors leading to beneath the Citadel

(INSIDE THE CITADEL)

We see Elder Lyons & the group walking down the hallways and entered an elevator as Elder Lyons pressed the down button

Elevator voice: going down.

Then as the elevator was going down, Elder Lyons turned and stared at Felicity

Elder Lyons: Felicity, you said to me that you're an expert on robots, am I right?

Felicity: yeah, I've built animatronics ever since I was 11.

Leela: Why do you ask, sir?

Elder Lyons: because back when we made the citadel our base in the Capital Wasteland, we discovered a robot that lied dormant down here and Steven, you know what robot I'm referring to.

Steven widened his eyes

Steven: But, Elder, it's not finished yet. Scribe Rothchild hasn't even given us a status report on it yet.

Felicity: so you're saying that you want me to help with finishing up whatever robot you have down here?

Elder Lyons: Precisely.

Felicity: (smiles and crosses arms) Well, whatever your robot is, I can probably understand what problem it has and how I can get it working.

(Later)

Felicity & Leela were having shocked looks on their faces while Kai just stared at the robot in awe...

LIBERTY PRIME MK 1

Felicity: There is nothing about that robot I understand!!

Kai: Yeah, what kind of robot is this?!

Steven: This.... is Liberty Prime. Our Scribes tried getting it back to working order but to no avail since we've tried everything power Liberty Prime up so far before you guys showed up 2 years ago.

Elder Lyons: And Felicity, this is why I'm asking both you & Dr. Li to find out what's wrong and get it working, will you do it?

Steven: For the Brotherhood... and for Brian's father?

(Brian is the Vault Dweller's name in this book, just to let y'all know)

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Felicity: (sighs) okay, I'll try my best.

(French Voice: One long fixer upper later)

Felicity & Dr. Li sighed as they wiped the sweat off their faces after finding the problem with his power source and fixed Liberty Prime earlier and turns out, he just needed a compatible fusion module to be installed into Liberty prime and after installing the module and activated the giant robot, everyone is now seeing Liberty Prime going up to the surface to fight against the Enclave

(watch this video)

https://youtu.be/EX3yJRXpSOQ

Leela: wow, it's really destroying everything.

Felicity: well, I've kind of upgraded a few things to Liberty.

Kai: like what?

and then...

Liberty Prime: Communism is a Lie!!

then he shot a laser beam from his visor at an Enclave Vertibird, destroying it as it blew up

Felicity: (nervous tone) well, I gave his right leg the ability to make ice cream like Circus Baby. i was gonna install it in Liberty Prime's chest, but he's a little too big to have an ice cream maker so, yeah...

Steven: Okay. Now let's just keep on moving.

he readied his laser rifled and charged after Liberty Prime brought down the plasma gates surrounding the Enclave Occupied Jefferson Memorial

Leela: (battle cry) LET'S GET THEM, AD VICTORIAM!!!!!

she and her group charged towards the Enclave soldiers and started firing at them

Felicity: FETCH, SIC 'EM!!!

Fetch pounced onto an Enclave officer and started mauling his face off, making the officer scream in agony

Enclave Specialist: WHAT THE?!

then Steven shot his power armor's fusion core, blowing him up as his body parts scattered everywhere

Steven: Okay Everyone, Let's get inside the memorial!!

Felicity: fuck yeah!

She screamed as she stomped on an Enclave soldiers head, killing him and everyone ran inside the memorial to take back Project Purity

(UNDER JEFFERSON MEMORIAL)

we see Steven & the gang, along with Brian (Vault Dweller) and some Brotherhood knights arrive underground the memorial where Project Purity is being operated and came across a squad of Enclave soldiers, and to everyone's shock, Colonel Autumn, who survived somehow

Colonel Autumn: You Again?!

Brian: (glares) yeah, me again.

Felicity: and us, Bitch!!

Leela, Steven & Kai (in his T-60 Armor) readied their weapons while having angry looks

Colonel Autumn: I don't know who you three are, but I can't say I'm surprised. You and your brotherhood seem hellbent on destroying everything our government has to achieve.

Kai: you mean using tech for evil?

Colonel Autumn: it doesn't matter if we do use it for evil, but there's nothing else to stop me from killing you all. So, Let's end this, shall we?

then he aimed his laser pistol and fired a laser beam at Steven's shoulder, making him yell in pain as he went on his knees

Leela: Steven!!

then the enclave squad started firing at the brotherhood squad, who fired back at them for shooting Steven while Leela dragged Steven away to avoid him getting shot again

then Kai & Felicity, who are both together hiding behind walls, nodded at each other as Felicity pulled out a flashbang grenade that she made herself and threw it at Autumn & his squad

Colonel Autumn: (confused) what the hell?

then the flashbang grenade blew up as it blinded the enclave squad

Kai: Okay, everyone!! Fire!!

Brian (Vault Dweller) nodded as he pulled out his 10MM pistol and shot Colonel Autumn's head off while everyone else killed off the remaining Enclave Soldiers

(AFTER THE BATTLE)

after Project Purity was activated and now under control of the Brotherhood of Steel, everyone is seen celebrating their victory with old, preserved champagne and all that sort of stuff people do at parties

Felicity: here's to our great victory.

Felicity then threw a raw bloody steak to Fetch while she chugged the champagne bottle she was holding in her right hand apparently, but as for Kai...

Kai: YEAH!!!

He yelled out as he chugged down a bottle of whiskey, then stopped drinking after he saw a whole makeout scene that made him smirk

Kai: Looks like our friends are having fun.

Felicity: Huh?

Kai pointed at something that shook Felicity to her soul and made her blush suddenly

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Steven & Leela were making out, while being drunk after many bottles of whiskey

Felicity: (blushes) Holy shit...

Kai: (shrugs) yeah, i can't believe it either.

Felicity: I never thought this would ever happen in a lifetime.

Kai: same here, friend. (nods) same here.

he said in agreement as he drank the last of whiskey in his bottle while Brian smiled because of three things. 1: he avenged his dad. 2: he saved the wasteland from the Enclave. and 3: he became a member of the Brotherhood of Steel and was dubbed as a hero

but then Brain's smile faded after he got a radio transmission alert from his pip boy and as he checked on what the transmission is called, his eyes widened and stared at everyone

Brian: uh, guys!! I think you see this, it's kind of important.

everyone was still partying, then a drunk Leela & Steven walked up to Brian as they sat next to him

Steven: (drunk) oh come on, Bri. Lighten up.

Leela: (drunk) yeah, it's a Victory Party. Why don't you show us later, okay?

Then she fell on the floor and laughed drunkenly, making Steven laugh for a bit and pick Leela up and they walk away as they resumed making out together

Brian looked at his pip boy and shrugged his shoulders after deciding to show his friends after the party is over

But soon, the Brotherhood of Steel will have to travel to the Earth Kai & his friends came from to save it from being taken over by Ruth, with the help of Frank Horrigan, of course