Akihito has managed to find his way to Mirai in the odd globe hovering above the town that is now Beyond the Boundary - but can he save her and defeat this most powerful of beings?
Between Mirai's ability and the fact that Beyond the Boundary was effectively born from Kanbara, just maybe, although it certainly isn't an easy fight as the pair struggle to make their way to the creature's core via myriad obstacles that stand in their way. Meanwhile, things are also getting pretty heated back in town as Fujima and his plan are found out, leading him into a battle with Izumi in particular that lays bare both of their own dark secrets.
Eventually, of course, good triumphs over evil on this occasion, with Fujima thwarted and beaten while Akihito literally beats seven bells out of the youmu that formerly resided within him thanks largely to his understanding of the shared fears that they've both been living with all of this time. However, things aren't looking quite so good for Mirai, or rather what remained of her when she previously fought Beyond the Boundary, which leaves Akihito feeling like all of his endeavours might just have been in vain.
Fear not though, because if anime loves to do one thing it's to deliver an incredibly lazy and ill-thought out cop out ending, and Beyond the Boundary is up there with the best of them, bringing Mirai back from the dead because... well, just because, okay? She's a main character, what if they want to make a sequel or something? So frustrating is this final twist that it threatens to undermine everything that has come before, while also bringing into relief some other rather lazy moments of conflict resolution - a shame, as up to this point the show's finale had delivered a lot of slick, well-realised action and a pretty solid ending to affairs.
In a way, this is the story of Beyond the Boundary as a whole - really rather good in places but let down by its weak points and with a tendency to rely on the same old character gags and lines to carry itself when it ran out of other options. Like so many of Kyoto Animation's other recent series, it's almost a show of two halves - the insipidly dull on the one hand, and the inspired on the other, with not quite enough of the latter to justify all of the former.