Even after resting Kasumi is still able to see the “real world”, so he leaves to do more research. This effectively put Asuha in charge because she’s going to cover for him in case anything happens, but she’s pretty nervous about all the responsibility.
Kasumi wanders some of the city ruins until he finds an old room with a working computer, but is not able to find anything in its system. The network appears to be all washed clear of incriminating information; the real documents must be hidden somewhere. Exploring the room, Kasumi finds a sliding panel behind which are stacks of booklets, filled with what he’s looking for. Things like “erosion rate” and “adaptability coefficient” are mentioned, and he sees a picture of people lying on the ground with a tag saying it was taken at the mana plant. Who left these documents there? And what are these terms referring to?
Down by the water, Ichiya is sitting with his notebook and Canaria’s cap, remembering Canaria and how much he cared for her. Asuha finds him and starts teasing him; Ichiya correctly 
points out that both she and her brother don’t know how to talk to people, and neither know how to take a hint. Asuha asks Ichiya for his help now that Kasumi’s away, but even after an alarm sounds warning of an impending attack, Ichiya refuses to help. Asuha leaves him with some taunting words.
At the command center, Aoi is trying to keep a grip on the situation, but it’s clear she’s in over her head as the attack is quickly ballooning out of control. Asuha shows up but she’s not much help either as she has little leadership experience. Then Ichiya makes his grand entrance and in no time has his fellow students scurrying to their places. Asuha’s a little annoyed at the way he’s taken control, but Ichiya is true to his narcissistic self and rebuffs her remarks.
Out in the field, Kasumi can see that their enemy is not really the enemy, thanks to his injured eye. He tells his comrades to leave so he’s the only one at that post. Down below Ichiya destroys a massive flying Unknown which was chasing two soldiers, and is about to launch another attack when the man he saved tries to restrain him from behind and prevent his attack. He is shot in the forehead by Kasumi however, enraging Ichiya and sending him flying over to Kasumi’s location.
The two allies face off against either, with Kasumi dropping hints that things are not what Ichiya thinks. The worlds they see are different, their enemy is not really their enemy, etc. When the Unknown “queen” makes an appearance and stands between them, Kasumi lets her go. His eye shows him that these Unknown are not their enemy after all; the wool was pulled over their eyes.
At the same time two large Unknown are attacking Asuha, and she’s definitely not a match for them. But are they really attacking her? As Asuha flies through the air, one of the Unknown breaks the chip on her neck, opening her eyes to the real world. Two down, one to go.
Ichiya uses a gravity attack which blows a hole through several floors of the building they’re fighting on, and both he and Kasumi fall into the hole. Then the Unknown “queen” from earlier shows up, and she’s drawn to Canaria’s cap, which Ichiya had dropped. Ichiya grabs Kasumi and is about to beat him up, but Kasumi starts humming Canaria’s song, saying he’s able to hum the tune because he’s hearing it. Because the Unknown is the one signing it.
Ichiya finally has the epiphany that this Unknown “queen” is in fact Canaria. And because now we know Canaria’s alive, we can presume that the other students who’ve “died” (Maihime, Hotaru) are not dead either. Perhaps they’re even some of the superpowered Unknown that Asuha was fighting earlier in the episode.
Canaria embraces Ichiya, then breaks the chip on the back of his neck. After the credits, we see him, Canaria and Kasumi standing on a rooftop looking at the city below. Everything is in ruins, with plant life carpeting many skyscrapers, and there are vines everywhere. The city has clearly been dead for a long time.
My thoughts: So now we know that the world our cast sees is fake, the question is now why? And who are the aliens who’ve used this fake world to entrap the children? Are there any real adults left at all? Who are behind the Unknown, and where are they coming from? I have so many questions and there are only 3 episodes left!!
Also, I hate to bitch about the animation again, but some of these shots are just wtf?? Case in point:
I dunno. This is an awesome show and I’m really, really enjoying it, but the drop in animation quality is distracting enough that it’s impacting my attraction to the show. And that sucks because we’re nearing the end so the action’s getting good, the plot’s coming together, but now faces are herpy derpy in many shots and it just sucks. I’m trying not to be super picky, really…