- This article is about the episode's article. For the episode's release event, see Episode 5: Necessary Solutions.
The fifth episode of Arknights' Main Theme is titled Necessary Solutions.
Synopsis[]
Attack on Lungmen[]

Peace must be restored through the L.G.D.'s success.
Rhodes Island Headquarters — Swire wakes Ch'en up from a nightmare with a splash of water and informs her that Reunion has occupied the headquarters of the Lungmen Guard Department. Swire blames Ch'en as the cause of the entire mess, since she had been knocked out during the assault and taken to a Rhodes Island cell to recover. Ch'en and Swire bicker back and forth over what the right course of action to take is, as well as Ch'en's culpability in the loss of their headquarters. Swire tells Ch'en that she ought to resign and pass her position as head of the Special Ops division to someone else, before storming off. Ch'en gets a call from her informant, codename XR-02, who tells her that Reunion lured him into a trap at Muk Wo Warehouse and that he is still holding time-sensitive intel.
Ch'en speaks to a Rhodes Island officer in order to coordinate a joint attack on Reunion. During the conversation, she reveals that she made the decision to defend Lungmen, and so chose to leave Amiya and her forces behind in the abandoned Chernobog sub-city earlier on — Amiya, Frostleaf, Meterorite, Jessica, and the allied forces are now considered missing in action. The Rhodes Island officer leaves in disgust at her actions, but Ch'en does not seem offended; even so, she decides not to employ R.I.'s help in the operation. Hoshiguma wonders why Ch'en decided to abandon Amiya's squad so decisively, and speculates that the orders were from Wei Yenwu; she says that while she appreciates what he has done, she will never respect him.
Ch'en and Hoshiguma launch a counterattack at Muk Wo Warehouse, the abandoned warehouse in Central Lungmen where XR-02 is being held hostage by Reunion. Ch'en confirms to Hoshiguma that the informant is actually Phal, who recently became an Infected and who Hoshiguma has known for ten years. However, when they breach the warehouse, they find Phal mortally wounded. Even though it is too late to save his life, the L.G.D. successfully retrieves the information he had on him, which points them towards the location of Reunion's bases.
Phal's intel also indicates that Reunion's objective is not just the construction of a forward base in Lungmen, but to look for an "extremely high value target." After fighting through some Reunion forces, Ch'en stumbles across Ch'en Estate, a mansion that belonged to her biological father's clan. Since Reunion had already torn through the house and caused structural damage, Ch'en breaks down the door to let herself inside. Although she tells Hoshiguma that she has no particular attachment to the estate, being inside its walls clearly leaves her reminiscing about her past. Ch'en comes across a cracked picture frame holding a photograph of herself and Talulah as children, hugging; knowing that Reunion had also broken into the mansion before, she wonders if the photo could have been what they were looking for.
After the brief detour, the L.G.D. forces continue their advance by capturing Paci Plaza, a nearby shopping mall (that is also owned by Swire's family) currently occupied by Reunion. During the battle, an explosion causes the floor beneath Ch'en to collapse, but she is saved by Hoshiguma, who holds the debris so it doesn't crush both of them. Hoshiguma is badly injured but insists she can still fight; she urges Ch'en to leave her behind to fend off Reunion and focus on recapturing L.G.D. Headquarters, but Ch'en refuses to abandon her. Ch'en admits that she has changed — after abandoning Amiya's squad, she reaccessed herself, and has begun to put more trust in people. For the first time, she calls Hoshiguma her friend, and vows to be her shield. Ch'en and Hoshiguma then fight off Reunion together; after the battle, Hoshiguma is tended to by the medic team, and Ch'en heads off to recapture L.G.D. headquarters without her.
Swire calls Ch'en, irate at all the damage that Paci Plaza had sustained during the battle and blaming "Ah Ch'en" for it. Ch'en promises to treat her to a meal as penance. Swire advises her not to throw her life away for the sake of the mission, revealing a more vulnerable side to their relationship, then wishes her good luck.
Chi Xiao Unleashed[]
After countless street battles, Ch'en and her team finally enter the headquarters. However, the officers immediately feel that there is something suspicious about the operation; the Reunion forces posted at headquarters seem barely prepared for a fight, and many floors are completely empty. They also receive intel that Reunion's temporary command center is on the rooftop. Ch'en senses the obvious trap, but takes the bait anyways. When she arrives at the rooftop, it does turn out to be a trap set by Mephisto. The L.G.D. is able to defeat almost all of Reunion's forces while weathering sniper attacks from Faust, but Mephisto resurrects the dead Reunion soldiers using his Arts and a powder. The resurrected soldiers start attacking again, now transformed from corpses into hulking monstrosities puppeteered by Mephisto and invulnerable to physical damage.

Ch'en unleashing her Chi Xiao
Knowing that the L.G.D. are about to be overwhelmed, Ch'en attempts to unsheathe Chi Xiao, the "dragon-slaying sword" imbued with Originium Arts. Wei Yenwu had given the sword to Ch'en in the past, and told her it should only be used against "worthy opponents." However, she is interrupted mid-cast and loses control over Chi Xiao; the blast injures her and some of the Reunion guards. Mephisto taunts Ch'en, reminding her that forcefully activating the Originium Arts inside the blade will only injure herself further. He tries to convince her to join Reunion, but Ch'en refuses to abandon her duties to Lungmen.
Boiling Blood, Looming Threat[]
Just then, reinforcements from Rhodes Island arrive on the battlefield via helicopter. Swire calls Ch'en, revealing that she had been coordinating with Rhodes Island behind her back and had rescued Amiya's squad from the abandoned Chernobog city. Now joined by Amiya, the Doctor, and the Elite Op Blaze, the tides of battle finally turn to the L.G.D.'s side. Mephisto is outraged to see that Amiya is still alive, and demands to know what FrostNova had told them. Meanwhile, Ch'en finally apologizes to Amiya for abandoning her in Chernobog. Mephisto presses Reunion to continue attacking, but knowing that the jig is up, Faust convinces him to retreat. They purposefully destroy the building and make their escape under the cover of explosions. Nevertheless, the recapture of L.G.D. Headquarters is the turning point of the invasion. Swire and Ch'en report their success to Wei Yenwu; during her report, Ch'en credits the joint efforts of Rhodes Island and herself in taking back the headquarters.
After the battle, Blaze confronts Wei Yenwu for using both Rhodes Island and the L.G.D. as bait in Chernobog to lure Reunion out — Wei had led Reunion to believe that the L.G.D. had been separated and that Lungmen was undefended, drawing Reunion to openly attack Lungmen. Blaze also brings up how Wei ordered the L.G.D. to abandon Amiya and her team to die, but Amiya talks her back down because they have no proof. Wei ends the conversation by reiterating that the relationship between Lungmen and Rhodes Island is still a political partnership, not a statement on the status between illegal Infected and the local authorities.
After returning to his office, Wei orders Swire and her squad to purge all the remaining Reunion forces out of Lungmen in a single day, without Rhodes Island's help. Despite Swire's protests, Wei insists it is essential as a show of Lungmen's strength.
Meanwhile, Wei anxiously awaits a message from Ursus. He tells Fumizuki of his premonition that the attacks on Lungmen and Chernobog is "the start of something bigger," i.e. a deeper conspiracy, possibly conducted by the Ursus Empire in order to expand its hegemony.
Operations[]
Main | 5-1 • 5-2 • 5-3 • 5-4 • 5-5 • 5-6 • 5-7 • 5-8 • 5-9 • 5-10 • 5-11 |
---|---|
Sub | S5-1 • S5-2 • S5-3 • S5-4 • S5-5 • S5-6 • S5-7 • S5-8 • S5-9 |
Inferno Mode | H5-1 • H5-2 • H5-3 • H5-4 |
- S5-7 and S5-8 are added with the release of Episode 06.
- S5-9 is added with the release of Episode 08.