WARNING: The following contains spoilers for 86-Eighty-Six Episode 8, “Let's Go,” now streaming on Crunchyroll.
After years of defying the odds and surviving countless battles against the Legion in 86-Eighty-Six, Shin and the remaining Spearhead Squadron – Raiden, Anju, Kurena and Theo – now prepare to march into war one last time in Episode 8. And it is indeed their last mission because the Republic's government has told them that any retreat will result in immediate execution. But why are they going this far?
Meanwhile, the Legion is testing out a new weapon, one that wiped out an entire platoon not far from Spearhead's location. Much to Shin's twisted pleasure, his brother Rei is among them. A distraught Lena desperately tries to do something, anything to help them survive or even abort this mission but runs into resistance from all sides – her scientist friend Annette, her Uncle, and even Shin himself.
The Spearhead Squadron has been ordered to march into Legion territory and continue fighting until they no longer can. The Republic's ultimate goal is for no 86 to still be alive when the war finally ends. If every last soldier dies, the government can erase its horrifying history as if it never happened. And of the few who still know the full truth, most – including Annette – just want to erase their own roles in the 86's oppression. This reckoning, and Lena's continued insistence on trying to help the remaining 86 avoid their inevitable fate, leads to one friendship's breaking point.
Despite their differing outward opinions on the 86's plight, Annette actually harbors deep psychological guilt from her past. As a child, she and her father were next-door neighbors to a family of 86, and they all got along well. The 86 family was a set of parents with two sons, and she was close friends with the younger brother. Annette says this family could feel each other's emotions, heavily implying her neighbors were Shin and the Nouzen family. However, when the Alba turned against the 86 and forced them into concentration camps for war, the young Annette gave in to peer pressure and turned away from her best friend in his moment of greatest need.
Normally so calm and apathetic, Annette flips out at Lena while revealing all this. She's long been a mystery, sometimes acting as Lena's more rational, realistic side and other times being frustratingly defeatist about changing their country's evil ways. Watching her past play out explains a lot, but she also despises Lena deep down. She claims to be sick of seeing Lena act like a saint and trying to change the world even though it's impossible, but deep down, she must know that Lena represents the courage and defiance Annette herself has always lacked.
Yet however defiant Lena continues to be, she is powerless to stop the 86's literally suicidal last mission. And more importantly, Shin and the others don't want it to be stopped. They knew all along this would happen if they survived, and now that Shin knows the Legion holding his brother is on the way, he eagerly craves the confrontation. He will continue to fight every Legion he can until he reaches and kills Rei – after that, he can die having lived a fulfilled life. Shin asked Lena for one single favor – to remember them – but despite the seeming inevitability of death for the Spearhead Squadron, Episode 8 does hint at an alternate future for their Handler.
After the Legion finishes off the 86 – The Republic of San Magnolia's lone defense – it's only a matter of time until the entire nation falls. But Shin tells Lena to go to the Eastern border, where the Legion's voices cannot be heard. It's not entirely clear why he says to go there in particular, but it's her chance to survive even if no one else does. For now, Shin and the others have made peace with their lives and begin their final, impossible battle that must end in death. 86-Eighty-Six's devastating climax is here.