Replacer

* Title screen
* Original title card

**Replacer** is the second episode of Mainstream. It introduces the Replacer Syndicate to the main storyline and takes place a few days after Episode 1.

## Synopsis

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> *Yoo Mina takes a day off and heads to the hospital when a Corruption Disaster sweeps through the entire city. However, lurking behind the disaster was a new conflict.*
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## Appearances

* Yoo Mina's sister (Mentioned only)
* Coffin Company
	+ Lee Sooyeon
	+ Operation Department
		- Lena Mackenzie
		- Chloe Starseeker
	+ Fenrir Squad
		- Yoo Mina
		- Joo Shiyoon
		- Hilde
	+ ALT Squad
		- Kim Sobin
		- Seo Yoon
		- Eujin
		- Xiao Lin
* Freedom Riders
	+ Amy Strickland
	+ Lee Minseo
	+ Hirose Aki
* Mason Mercenary Office
	+ John Mason
* Jane Doe (Mentioned only)
* Tommy and the Losers
* Finley Hired
	+ Mark Finley
* Replacer Syndicate
	+ Replacer Knight
	+ Replacer Queen
	+ Project Terraside (Mentioned only)

## Plot Summary

### Act 1

Yoo Mina is on leave, visiting her sister in a Corruption Disaster Rescue Hospital in Old Seoul. After paying for her sister's medical bills, Mina leaves to eat but encounters Kim Sobin. While Mina is initially distant towards her due to ALT Squad's actions during the fight against Ministra, Sobin assures her that her team meant no harm. Mina later asks what Sobin was doing, and Sobin explains she was getting medicine from the hospital. When Mina sees the immunosuppressants Sobin ins carrying, she questions her why ALT Squad needs such medication that when they are interrupted by a loud noise. The two investigate and discover that a Corrupted Object has appeared, which surprises Sobin as she thought it was impossible as the city uses a Grand Suppressor to prevent C.O.s from surfacing in the Normalside. A blonde girl named Amy Strickland comes along and asks the two of them for help in taking it down; Sobin and Mina agree to help though the latter is reluctant.

After taking care of the immediate threat, Amy leads Sobin and Mina to her team—consisting of Amy herself, Hirose Aki, and Lee Minseo—who are already in combat with a group of C.O.s. After Mina and Sobin aid the group against the C.O.s, the three girls properly introduce themselves as the Free Counter Society, known informally as Freedom Riders, a mutual aid group dedicated to helping struggling Counters. Sobin accidentally calls them the Free Riders, causing Aki to correct her. Amy asks for Mina's help against the C.O.s. Mina refuses since she won't be paid and is only convinced when Amy mentions that the C.O. threat could damage the hospital. The group realizes that the TASKFORCE companies aren't responding despite the clear CO threat, so Mina and Amy decide they need to handle the issue themselves. The group gets the nearby C.O. horde's attention, and tries to lure the horde out of the city, but the group is blocked by a phase barrier, a defensive technology fueled by energy from large quantities of Eternium. Sobin explains that the barrier's presence doesn't make sense as they're typically meant for dimensional ships rather than entire cities.

The group tries to hold off the C.O. horde when they are finally rescued by a group of mercenaries. One of them orders Mina's group to go to the nearest shelter. Mina nearly causes a fight due to the mercenary's unusual hostility, but Amy defuses the situation and agrees to comply. Aki and Minseo are glad that an apparent TASKFORCE company is responding to the danger, but Amy and Mina conclude that the mercenaries are acting strangely.

### Act 2

At the shelter, there's an announcement that Finley Hired is handling the elimination of Corrupted Objects in the area. Amy and Mina find the handling of the situation odd; the City Guard should have mobilized the city's Counters in response to the CO threat as per normal protocol. They decide to escape the shelter and meet with City Management. Mina has Sobin, Aki and Minseo attack the guards as a distraction while she and Amy slip away wearing bunny suits. Sobin's group causes significant damage to the mercenaries but retreat when Sobin runs out of ammo.

After getting past the guards, Mina and Amy find a mercenary named John Mason, who was captured by Finley Hired. John explains that Finley Hired purposely caused the Corrupted Objects to appear and proposes that they leave so he can get help frpm his client. However, Amy notes that the phase barrier will not let them leave, so the group decides to search and destroy the Inhibitor, the power source, so they can escape. Mina then calls up Sobin's group to see how they are doing, and Minseo says that Sobin found an ammo stash and has resumed attacking the mercenaries.

Mina's team links back up with Sobin's, and they all go to the Inhibitor. They are intercepted by Finley Hired mercenaries, some of which turn into C.O.s. known as Replacer hybriders. Kim Sobin is shocked to see the hybriders and has a nervous breakdown. Minseo and Aki help Sobin while Mina, John, and Amy fight the hybriders. Mina's group destroys the Inhibitor, and they search for a nearby truck to leave. Sobin continues to babble incoherently, but is brought back to her senses when slapped by Mina. Mina sees Amy picking up something off the ground; Amy says she just wants to keep a souvenir.

### Act 3

Once the group reaches the city outskirts, Mina asks John what those Corrupted mercenaries were. John reveals that they were soldiers created by fusing humans and C.O.s. He then calls his client Blackbird for help. Blackbird tells John that City management has issued an arrest warrant for him and demands to know what's going on. After John explains the situation, Blackbird says he can remove the arrest warrant if John can find proof of the City Management's corruption and provides the location of a rendezvous point. Soon after, the group is ambushed from Tommy and the Losers.

John persuades Tommy and his friends to help him rebel against City Management. As the group begins their ride to the rendezvous point, Mina asks Sobin about her reaction to the hybriders; Sobin claims she was reminded of her encounter with Ministra and Spira. As they approach the rendezvous point, Mark informs John that he and his men are under attack by the hybriders and their failed counterparts (known as "collapsers") and hiding in a nearby warehouse. The group arrives and defeats the C.O.s.

John rescues Blackbird, who introduces himself to the group as the Mark Finley, a CIA agent and the President of Finley Hired. He explains that his predecessor had betrayed the larger Finley Company and put Finley Hired under the control of the Replacer Syndicate, the terrorist organization behind the hybriders; Mark had been assigned to take care of him as well as any other possible traitors and hired John Mason. The Replacer Syndicate had previously wiped out small towns in their effort to create their hybrider army and is planning to turn KS-1's population into hybriders.

As the group considers their next move, they are interrupted by Replacer Knight via a hologram. Mark tells Knight she will pay for her crimes and says he sent an elite strike team against her, but Knight reveals that she had already killed them all. Knight realizes that Sobin, whom she calls the Alternative Type, is among the group and tells one of her troops to contact the Replacer Queen immediately. Queen tells Knight to change her priorities to capturing Sobin alive.

The group leaves the area for the city outskirts. Mina is determined to return to the city despite the danger while John proposes she call her TASKFORCE company for assistance.

### Act 4

Lee Sooyeon initially refuses to send forces to help but instantly changes her mind when she sees the amount of money Mark has paid Coffin Company in advance. Sooyeon informs Shiyoon and Hilde of the new job and departs in the Coffin to oversee the operation. Lena protests because the air traffic controller is refusing to allow their ship to enter KS-1 airspace, but Sooyeon has some troops incapacitate Lena and take her to the infirmary, scaring Chloe into compliance.

Mason takes Aki and Minseo to the City Management building to uncover evidence of the City Management's corruption, while Amy, Sobin, and Mina link up with Coffin Company forces. Aki and Minseo are worried about parting with Amy, but Amy assures them that she will never abandon them. Seeing Mina's distress over the hospital potentially being attacked, Seo Yoon tells Mina that ALT Squad will hold off the Replacers while Fenrir Squad secures the hospital. Meanwhile, Chloe observes Finely Hired and City Management's criminal actions and announces they will be designated as terrorist organizations.

Fenrir Squad and Amy rush towards the hospital. As Mina stops to breath, Amy offers to stay behind to cover Mina. However, Replacer Knight arrives and smashes on top of Amy, apparently killing her. Knight asks Fenrir Squad where Sobin is upon seeing that she is not present before engaging them in battle. She later escapes when she learns of ALT Squad's presence. Afterwards, Mina and Hilde realize that Amy's body is gone, and the former vows to avenge her.

Knight finds ALT Squad and fights them, taunting calling them test subjects and threatening to return them to the Replacer Syndicate. Fenrir Squad arrives to reinforce ALT Squad, and in response Knight creates stronger hybriders. Hilde is shocked at the sight of the hybriders, making Shiyoon ask if she's seen them before though she denies it. Knight then transforms into a stronger hybrider herself but is unable to overcome Coffin's forces and is executed by Mina.

The crisis is averted and the Administration begins recovery efforts for the city. Yoon thanks Mina for her assistance and is about leave when she encounters John. John, who is aware of ALT Squad's true background, tells Yoon that he saw her take a VeriChip from Knight's body and offers to trade information on Project Terraside in exchange for it.

During Amy's funeral, it is revealed Amy survived and that "Amy Strickland" was an undercover identity. As Amy watches the funeral outside of notice, she calls another individual by phone, and tells them that she recovered the Factor Extractor Core from the Inhibitor so their plan can move forward.

## Stages

* Act 1
* Act 2
* Act 3
* Act 4

 1-1
 1-2
 1-3
 1-4

 2-2
 2-3
 2-4

 3-2
 3-3
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