She returned to Sanctuary to pick up Nick, then they went to Valentine Detective Agency for her hazmat suit for their trip back into the Glowing Sea. Virgil was extremely grateful she remembered their deal and immediately injected the serum. He told them it might take a few days for the serum to work, so he suggested they return later to see if it worked. They left him and headed back for Sanctuary to see if Sturges was done.

As they headed for the Tinker's usual haunts, Preston met them on the road—he looked excited. "Sturges broke the code and found a way in; come on." He walked with them to find Sturges, reading something on a terminal.

"Preston told us you found a way into the Institute," Briar Rose began.

He turned. "That's right. I was hoping I'd find something worthwhile after all that time spent cracking the encryption. And I did. One of the things in the data you stole was a plan of the whole Institute complex—including the older sections that used to be part of C.I.T. Turns out, they're still using an old water pipe that runs out to the river—brings in cooling water to their reactor. Its entrance is underwater but is blocked by a security grate. Also, the whole pipe is labeled 'high radiation danger'."

Nick skewered him. "You don't believe that warning's real?"

He shook his head. "From what I've read, no; it's a way to keep out trespassers. There isn't any other way in that I could find, so it's this or nothing. I did manage to pull the code to open the grate. So all you have to do is to survive the trip." He pulled out another holotape. "Soon as you get in there, you need to access the main Relay control and use this holotape to teleport everybody into the Institute."

She looked at the holotape in his hand, waiting for her to take it. The surrounding men remained quiet, understanding her hesitation. Taking it finalized her decision to destroy the Institute and killing Shaun. Her son. Her flesh and blood she has fought so hard to find. Could she do this?

She didn't really have much of a choice. Shaun had destroyed lives through the Institute and with the way he looked down on the Commonwealth like they were better, meant he had no intentions of stopping. He said the Institute had the Commonwealth's best interest at heart... but to her, it seemed like they wanted to wipe them out. Just because he was her son didn't mean he could have a free pass—like any other criminal, he had to pay for his crimes.

Briar Rose took the holotape from Sturges and looked at him. "Where do I need to go?"

***

Sturges' directions led them East along the Charles River. She and Nick looked down at the murky water hiding the pipe providing entrance into the Institute—they had left Dogmeat behind in Sanctuary with Mama Murphy. Once the Relay was opened, Preston, Sturges, and a slew of Minutemen would teleport in. Then the fight for the future of the Commonwealth began.

Nick looked at her after observing what stood in their way. "Ready, Flower?"

After thinking it over, Briar Rose sighed heavily. "No, but I can never be ready to kill my son."

He placed a hand on her shoulder. "Don't think of this as that."

She looked at him. "But that's what I will be doing, right?"

Nick couldn't respond; Briar Rose looked back down at the water. "Let's just get this over with."

She launched over the railing and fell a few feet before hitting the polluted water; Nick splashed beside her not a second later. After re-emerging, Briar Rose was careful not to swallow any of the foul water as she gulped in some air and dunked under.

Even though hard to see in the murky water, they found the pipe jutting out into the river a few feet under the surface. She looked to make sure Nick had seen it too; with him right behind her, Briar Rose swam into the pipe. They followed it into a chamber with multiple pipes branching off from a pool in the middle.

Briar Rose climbed up out of the water onto the ledge overlooking the pipes; Nick stayed in the water so he could see which grate opened. Numerous safety and 'radiation danger' signs were posted around the room and some on the pipes. A utility room closed off by a metal door sat to their left, but their attention was on the terminal bolted into the brick wall.

Standing there dripping wet and getting colder by the second, she typed in the code to open the grate. Metal screeched as a grate opened; she turned to see Nick swim over to a certain pipe.

"It's this one."

She walked back down into the water and followed Nick as he swam into the pipe's darkness. Briar Rose gulped in air again when the water level neared the top of the pipe. Her precaution came at the right time, for a current suddenly sucked her down. She didn't remain submerged for long; air hit her face as she dropped into another pool with the water relentlessly pounding her back.

Nick's face appeared through the waterfall. "Don't speak. We're not alone, but are you okay?"

She nodded, and he motioned for her to follow him before he disappeared through the wall of water. Briar Rose mimicked him by nearly submerging as she swam out.

They had cascaded down into a dimly lit underground chamber with pipes snaking throughout the room. The 'others' Nick had mentioned with them were Feral Ghouls—some sat at the edge of the pool eating rotten fish.

As quietly as they could, she and Nick swam to the opposite side of the Ferals and climbed out. Sturges had wrapped their guns in some covering to protect them from the water. After freeing their weapons, they killed the Ferals without hassle.

Their long trek through the brick tunnels, they had to kill many Ferals, Mirelurks, and even Radroaches. When the channels began to turn drier, their opposition turned into synths. By meeting them, it meant they neared the actual Institute.

One door led them into the Relay room Briar Rose had first teleported into a week ago—they came through on the side that looked in-progress. After making sure it was clear, Briar Rose stepped up to the control panel, inserted the holotape Sturges had given her, and initiated the remote relay sequence.

Within seconds, blue light appeared in the Relay room and Preston, Sturges, and Minuteman after Minuteman appeared. They stepped out as others kept teleporting in; Preston looked around as Sturges hurried to take Briar Rose's place at the control panel.

"So this is the Institute," he said when she approached him. "They could've just held out down here forever. Why'd they need to come mess with the Commonwealth?"

"They think they're better than anyone else," she said.

"They should've read their history. That hasn't ever turned out well. In any case, here we are; no turning back now..." He turned to her as he pulled out some box and handed it to her. "You're going to need this. It's a Fusion Pulse Charge; once it's attached to the reactor, it can be detonated remotely. You get that on the reactor, and we can trigger an explosion that'll destroy everything the Institute has ever built. Just make sure we give the civilians a chance to escape before we blow the place. We're not here to commit mass murder.

"We'd better hurry; they're going to realize what's going on before too long." He looked over at the Tinker already working at the terminal. "Sturges, you better get to work on this teleporter of theirs. We need that thing running as soon as possible."

"Got it. Y'all remember the path you've got to take?" They nodded. "Well, then, good luck and be careful."

They hurried down the steps and took a left in the room with the elevator to slip into Old Robotics. The forgotten division provided an opportune path for a large number to enter the Institute through Bio-Science.

But their intrusion had now been noticed, for many Institute synths waited for them. Nick hacked into an old Sentry Bot to make it fight for them and help lower the playing field. When they finally reached Bio-Science, more Institute synths fired on them as scientists ran for cover. Someone had even released the synthetic gorillas that charged at them and pummeled some Minutemen.

In the actual Institute, it became a war zone—the red beam of the laser muskets contrasted with the blue beam of the Institute laser rifles. Synths and Coursers alike tried to kill them. It took a while before the air grew still again with the stop of fire when the synths and Coursers lay dead. Quite a few Minutemen had been lost, too.

"Hey, guys," Sturges came on over the intercom. "Found the reactor... Looks like you need to get yourself into the Advanced Systems area. Only, well, it's locked. I can't override it from here; the command can only come from the Director's personal terminal. You're gonna need to get access to it somehow."

Preston looked at her. "Do you know where that is?"

She looked up at Shaun's room—the Director's—overlooking them. "Yeah; I'll get it. Follow the blue line to Advanced Systems and wait for me there."

As Preston and the remaining Minutemen did as she instructed, Briar Rose and Nick headed for the glass elevator in the middle of the complex. It was a silent ride down, trek to another elevator, and ride back up.

She didn't know how Shaun would react to seeing her against him. He would undoubtedly be angry. But would he be so infuriated that he would try to kill her? She prayed he wouldn't force her to kill him right there—she didn't think she could shoot her son.

The elevator doors opened and Briar Rose took a deep, steadying breath before stepping out and ascending the stairs. At the top, she turned, expecting to see Shaun standing at the window, watching the infiltration below him. Instead, she found her son lying in a bed, sickly pale and tired. A medicine drip stood beside him with a tube injected into his arm.

Seeing him on what looked like his deathbed took away the speech Briar Rose prepared to make about her reason for doing this. She walked over to him, shocked and numb.

His eyes fluttered open at feeling her presence and looked at her, reflecting pain, sorrow, and anger. "I didn't expect to see you again." His voice was weak and strained. "Come to see the reactor, have you? We got it working without you."

Her hands shook. "What's happened to you? Are you sick?"

"Don't pretend to care now. You had your chance to help me and cast me aside instead. It's not enough I lay here dying... Now you plan on what, destroying everything? Tell me then: under what righteous pretense have you justified this atrocity?"

Her already prepared speech came to her lips. "It's for the greater good. The Commonwealth deserves to determine its own fate."

He scoffed. "Spare me. You've spent time up there. You know as well as I it's doomed." He paused. "Well, none of it matters now, I suppose. You'll accomplish your task, and ruin humanity's best hope for the future. The only question left then is why you're standing here. Is it regret, or did you just come to gloat?"

Briar Rose sat on the edge of his bed and took his frail hand. "Shaun, if you help me, fewer people will die. Will you?"

"Why would I ever consider helping you?"

"Help me, and I promise I'll protect any survivors to the best of my ability."

Shaun hesitated, then sighed. "Very well. The terminal behind me... enter access code 9003. That will disable some of the synths. Now, go... Just leave me."

Out of the corner of her eye, she saw Nick move over to the terminal to enter the access code; he also activated something else for an 'emergency evacuation' sounded over the intercom. Shaun had turned away from her in disgust, but Briar Rose leaned over to hug him. He was still her son, and she loved him, no matter what.

"I'm so sorry, Shaun." Tears and emotion made her voice watery. "I wish none of this had ever happened."

At first, his form had tensed but then he softened; a hand reached up to hug her back. "Me too, Mother. Me too."

Him agreeing nearly broke her. Briar Rose clung onto him as the tears flowed into his shirt.

"All right! Good job! Looks like that's opened things up enough for you to reach the reactor," Sturges said. "Some other good news: I've almost got the teleporter working. Should be ready to pull you out whenever you need."

Nick gently grabbed her shoulder. "Come on, Flower; we need to go."

She let him pull her off her dying son. Shaun looked heartbroken to have her leave, but sobered up as he looked over at Nick. "Take care of her, synth... please."

"I'll definitely do that."

Briar Rose's fingers slowly slipped from Shaun's as she backed away. She held in a sob when she turned her back on him, held close to Nick's side.

They made their way down a spiraling staircase—past immobile synths that had been shut down—to meet the others waiting at the door to Advanced Systems. She wiped away any remaining tears as they approached and refocused on the fight before them. Preston placed a hand on her shoulder for comfort before they opened the door.

Like before, they had to fight their way through Advanced Systems and into the reactor room. The fight in there was more intense—one of the synths high up on the metal catwalks had a missile launcher. After clearing out the synths, Nick was the only one who could get close to the reactor because of the high radiation. He worked on a nearby terminal to power down the reactor and lower the level of radiation emitted. As soon as the doors slid open, revealing the reactor's vulnerable core, Briar Rose attached the Fusion Pulse Charge.

"We need to get out of here, and fast, before they figure out what we've done," Preston said when she stepped out and Nick shut the doors behind her. "Sturges! You reading me? We're done down here. Zap us back to the relay room!" he said to the air.

Blue light blinded her and a roaring filled her ears as they were teleported back into the relay room. Some Minutemen that had been left behind to guard Sturges looked at them when they appeared.

"All right, Sturges, we're done. Get us the hell out of here," Preston announced.

Sturges looked at them over the control panel. "I would, man, but... uh, this kid showed up; says he's Briar Rose's son." He nodded over to his right.

Confused, Briar Rose stepped out to see the synth-child Shaun—he looked scared.

"Please, Mom... don't leave me here! I want to go with you."

She was taken-back; first he had refused her, now he accepted her. "Why are you calling me mom?"

His brow furrowed. "Because that's what you are; Father said so."

Shaun had reprogrammed him into believing she was his mother—he thought this synth-child could take his place as her son. She didn't know whether to be touched that he had thought to apologize by giving her the son she had been robbed of, or disgusted at the idea Shaun had thought this synth could pretend to be her son.

Nick stepped up beside her. "Bring him, Flower; we need to go."

She looked at him. "But he's a synth."

"So am I."

Briar Rose stared at him, feeling guilty at accepting Nick and refusing the synth-child Shaun. She looked back at the boy—maybe she could start a new family with raising him as hers and Nick's son. To make it easier, she had to stop referring to him as the synth-child Shaun; just Shaun.

"All right, you can come with us."

His eyebrows shot up. "Really? Do you mean it?"

She nodded. "Yes, I mean it. Now let's get out of here."

The syn—Shaun, ran up to throw his arms around her. "I'm glad you were here to save me."

She hugged him back—already feeling her heart warm at his touch. She looked over at Sturges. "Let's go."

He nodded. "I'll teleport you to the detonation site, then set the relay to shoot the kid back to Sanctuary—we'll get him a change of clothes and look after him. You press that button extra hard when you get there. See you on the other side."

Briar Rose told Shaun she would see him soon, then stepped into the Relay with Nick, Preston, and a few Minutemen. With blinding blue light and another roaring, they were teleported outside to fresh air and strong winds. She found them on some tall building's [terrace] and able to look over all of Boston. The C.I.T. ruins could be seen as a small miniature.

"Sturges figured this was a safe distance outside the blast radius," Preston said. "Whenever you want to see 'humanity's best hope for the future' go up in smoke, just hit that button."

With another deep breath, Briar Rose walked over to the detonator waiting on a barrel. She pressed the button to ready the charge, then her hand hesitated—she couldn't force her finger down.

Nick's robotic hand laid over hers; with his support—also destroying the one place that could help him and provide answers—Briar Rose pressed the button.

Like when the bomb fell to start all of this, the horizon lit up in a blinding flash and a loud boom. The light faded and they could see the giant cloud shooting up into the sky and a powerful shock wave emanating from the epicenter.

Briar Rose didn't register the cheers and whistles from the Minutemen that they had done it; she just kept her eyes on the dispersing cloud with her head tucked under Nick's chin. It took a good long while for the smoke to clear and a giant crater replaced where the C.I.T. ruins and the Institute used to be.