Never mind the pair of mental models on their doorstep, the armed forces have only one target in mind as this week's Arpeggio of Blue Steel begins - little kid-cum-artificial intelligence Makie.
Having befriended her however, Haruna in particular has no intentions of letting Makie come to harm at anyone's hands, and thus she sets about attacking the forces which have come to dispatch this child genius. Protecting Makie is easier said than done when the girl herself demands that Haruna doesn't bring those trying to kill her to any harm, and Haruna's thought processes are further shook up as Makie pulls away from her after realising that she is, in fact, part of the Fog.
Nonetheless, Haruna stands firm in her desire to protect her new friend, creating a decoy to lure troops away so that Makie might escape with some help from Kirishima. This proves to be easier said than done, and once she realises what's happening Makie similarly refuses to leave Haruna in danger, leading to a dangerous reunion that puts them right in the middle of the concentrated armed forces stacked against them. With her powers dwindling, all Haruna can do is cry out for help from anyone in a last desperate bid to protect Makie... enter Iona, her crew, and a whole lot of weaponry.
As cool as parts of this week's episode were, I think Arpeggio of Blue Steel would do well to stick to playing in water in future - even at their best there's something far less satisfying about watching the show's Mental Models fighting on land in their human forms (or teddy bear forms, in Kirishima's particularly ridiculous case). I'll give this episode some credit for continuing to progress the show's story as it pertains to developing the Mental Models characters and sense of human emotion, but I can't pretend that it's highbrow stuff, and I'd still swap any plot development for another tense naval battle or two in an instant.