- Chapter 1: A Battlefield with Zero Casualties
Lena was asked by her superior and her late father's close friend—Jérôme Karlstahl—to take command of the elite Spearhead Squadron after the previous Handler resigned. The Spearhead Squadron was an elite unit consisting of veteran Processors assigned to the battlefields with the heaviest combat. The squadron's infamous captain—Undertaker—was rumored to be the cause of a Handler's suicide. As no other Handler would volunteer for the role, Lena would take the assignment out of a sense of duty, despite Karlstahl giving her the option to refuse.
- Chapter 2: All Quiet on the Skeletal Front
She resonated with the Spearhead Squadron for the first time on May 22nd RY 367; while she couldn't be of help on that day's battle, her initial suggestion of where the squadron should be deployed was noted to be a competent answer by Wehrwolf. She continued to check in on the squadron nightly and engage them in conversation. While Lena genuinely saw these nightly Para-RAID synchs as her way of humanizing the Processors, the members of the Spearhead Squadron saw it as a way to kill time, merely superficial niceties.
- Chapter 3: To Your Gallant Visage at the Underworld's Edge
With the intention of fully supporting the Spearhead Squadron, Lena spent her time researching Legion formations and reinforcement rates, as well as finding a map of the Eastern Front's First Ward.
Relations between her and the squadron would sour after Kirschblüte's death on June 15th. She was severely berated by Laughing Fox for even thinking to give words of mourning to the squadron, as he considered that—in the heat of the moment—she did not have the right to do so as one of their oppressors. Without realizing, Lena had made Kirschblüte's death about Lena's failure, putting the focus on herself instead of their deceased comrade. She also still adheres to the prejudices implanted by the Republic subconsciously, never even considering to refer to them by anything but their Personal Names. She disconnected from the resonance once requested by Wehrwolf, after which she would have time to reflect on her world view and ideals. Even with Annette and Karlstahl's dissuasion, her conviction to help the squadron remained firm.
She nervously reconnected with Undertaker later that night, apologizing for her behavior and requesting for the names of the squadron's members. Sensing that Lena was eager to prove herself once more to the squadron, he gave her a chance and introduced his comrades' names to Lena one by one, also telling her about his promise to carry the tags of his fallen comrades. With his help, she would manage to repair their relationship and set a true foundation for their interactions moving forward. Undertaker would eventually introduce himself as Shinei Nouzen, to which Lena would ask if he was related to a Processor by the Personal Name of Dullahan—Shourei Nouzen. He confirmed that Shourei was his brother and told her of his death five years ago. He admits to Lena that he does not have any plans once he was discharged, only that his current goal was to search for his brother. Lena was confused by what he had meant, but Shin simply deflected.
Chapter 4: I Am Legion, for We Are Many
Annette sends a message to Lena, asking her to join her in dress shopping for the upcoming Revolution Festival. Lena considers, but chooses to decline in favor of going over the mission reports and data files, certain that the information will help keep everyone alive. Annette reminds Lena that devoting herself to the Eighty-Six won't do her any good.
Later, while chatting idly with Shin, he presses her on why she won't go, and Lena admits that she's nervous an attack might happen during the party. Shin tells her that what happens inside the walls doesn't affect what happens outside them, and that her analysis for the Eighty-Six shouldn't take up all of her time. Lena worries that her work is unnecessary, but Shin assures her that her perspective is priceless. Lena begrudgingly agrees to go to the party.
As they continue to chat about the festival, Shin mentions remembering fireworks, and Lena realizes that Shin must've lived in the First Sector. The topic turns to his brother and Lena talks about Rei's desire to return to Shin, which Shin seems to doubt, much to Lena's confusion. Lena notes a sound in the background of their talk and realizes that Shin is servicing a rifle (which the Eighty-Six are not allowed to carry), even though he should be on patrol. Lena gives him a pass for the patrols and the rifle, trusting Shin's judgement and that the rifles are necessary, which surprises him.
Sensing an incoming Legion attack, Shin calls a strategy meeting that Lena attends. Shin asks Lena to cut off her Para-RAID for the mission, as it's dangerous to stay connected to him with the number of Black Sheep present, but Lena refuses. During the mission, Lena hears the ghostly wails of the Legion for the first time, which overwhelms and terrifies her until Shin cuts the connection. The last voice she hears is Kaie's.
It takes Lena until the evening to work up the courage to connect to Shin. He explains to her that he can hear the voices of ghosts beause he himself died once. The Legion is comprised of ghosts. When Lena presses for details, Shin elaborates that the central processors of every Legion is based on the human brain, and that in order to overcome their operational hours limitation, the Legion have taken to recovering the heads of fallen soldiers and copying the structure of the brain to use as replacement central processors. Shin goes on to tell Lena that the Republic is going to lose the war, as the Legion will not shut down in two years as predicted with the replaced cores but the Eighty-Six will run out soon enough. Lena says that all they need to do is win before that happens, so they should survive the war together.
Chapter 5: Fuckin' Glory to the Spearhead Squadron
During a battle, Lena struggles to adjust to sounds of the Legion heard through Shin. Kurena chides her for it, and when Lena asks how the others can bear it, Kurena explains that the Eighty-Six hear the sounds of dying comrades all the time, with or without Shin, so none of them find those screams unusual.
Lena later resonates with the boys of the squadron, not including Shin, who went to sleep early. Lena is baffled as to why the squadron hasn't received any reinforcements despite the losses, and she promises to push harder for restocking and personnel. The boys give a noncommittal, despondent response.
Some time after, Lena is attending a party, athough she is quite bored by it, making explicit efforts to avoid joining in the party by wearing a black dress fit for a funeral and refusing to drink or initiate conversation. Shin resonates with her during the party, both because she hadn't called at the usual time and to thank her for the fireworks she sent them under the guise of 'special ammunition'. They compare the sights of the fireworks and Shin is grateful they can give their fallen comrades a proper funeral artillery salute. He asks Lena to never forget them, and Lena swears she won't, but before that, she won't let anyone else die.
Unfortunately, four more died later that day in battle to a new, unknown type of long-distance artillery Legion. Lena is more confused and enraged by the lack of reinforcements then ever, so Shin, after confirming with everyone that it's okay to tell her, explains the truth: reinforcements will never come. The Spearhead squadron is an execution ground.
Chapter 6: Fiat Justitia Ruat Caelum
Shin goes on to explain that the promise of restored rights is a ruse by the Republic. Lena can't believe it, until Theo points out that she's never seen any Eighty-Six living within the Eighty-Five Sectors, despite how long the war has been going on, which she realizes shouldn't be possible. They tell her that Spearhead is a place where namebearers are forced to fight until they die. In the event they survive, they're given a special recon mission into Legion territory with a 0% survival rate. Lena is appalled that they would keep fighting despite knowing this, asking them why they don't try to run or get revenge. Raiden explains that none of them want to stoop to the same level of the white pigs by letting them get slaughtered in revenge. If their choices are to die fighting or to die giving up, then they'll fight to the end, even if it means protecting the white pigs. It's their pride as the Eighty-Six.
Lena goes to visit Annette, begging her to help her stop this, but Annette snaps at her and tells her there's nothing they can do. She tells Lena about the boy who used to live next to her, who was a close friend but was an Eighty-Six. Unable to deal with the bullying from her classmates for being friends with an Eighty-Six, Annette snaped at this friend, and when her father considered taking them in, Annette refused to let him. She goes on to tell Lena about the human experimentation in creating the RAID device that led to the deaths of countless children and drove her dad to suicide. At the end, Annette tells Lena that her interference with the Eighty-Six just made things worse and she would've been better off doing nothing at all, and that she doesn't want to see her again.
Later, Lena receives the order for the long-term reconnaissance mission for the spearhead squadron. She goes to Jérôme Karlstahl and begs him to retract the order. He tells Lena that the Republic is much better off if none of the Eighty-Six survive, as if there are no survivors, then it'll be as though the Republic did nothing wrong. Lena is aghast, but Karlstahl points out that all citizens are compliant in this by turning a blind eye, and says that if her words of hope and ideals had any real effect, then she wouldn't be coming to him for help. Lena is forced to leave.
When resonating with Shin about the upcoming mission, she begs Shin once again for him and the others to run away, but he tells her there's nowhere else for them to go, and that to them this mission meant freedom, not death. They have to fight. Lena guesses that Shin is after his brother. He confirms it, and asks Lena not to resonate with them during the battle as he doesn't want her to hear his brothers last words. He adds that he can't hear the Legion beyond the eastern border, suggesting there might be someone alive out there and that they might come to help, asking Lena to stay alive until that happens.
Chapter 7: Good-bye