At last, the exact nature of the link between Black Rock Shooter's world and reality is made clear, as Mato is sent into the breach to save her distraught friend Yomi. But what effect will this have on Mato herself?
The answer seems to be - not good. Perhaps due to the mental anguish of killing Yomi's "Dead Master" cipher within this netherworld, Mato seems unable to return to reality as things deteriorate, with Saya the next target within Black Rock Shooter's sights. This clearly isn't what Yuu was expecting when she sent Mato into that world, and thus she carries her friend's comatose body to Saya as her only port of call in this particular storm.
While Saya isn't exactly thrilled at this development, it seems that there's no other option than to throw herself into Black Rock Shooter's world in an attempt to speak with and save Mato - a decision which gives this episode the opportunity to enter flashback mode as we explore the relationship between Saya and Yuu, the latter of whom appears to be the origin of this strange other world which Saya has sworn to protect in the face of the difficult mental pressures put upon her friend. While calling out to Mato is one thing, extracting her from the world in which she is now part is a much tougher proposition, especially as Saya's alter-ego Black Gold Saw finds itself protected from an arguably unexpected source.
Although I've been calling for Black Rock Shooter to explain the link between its two worlds from the very start, I can't say that this episode has really helped its plot from an "actually making sense" perspective - although things are certainly much clearer for the most part (with Yuu the other world's "owner" which others have been deliberately dragged into via mental pressure in some shape or form), the entire setup still feels like a contrived way to shoe-horn the Black Rock Shooter concept into the midst of a bunch of over-wrought teenage melodrama and there isn't really a lot that can be done at this juncture to fix that. Still, if nothing else this was perhaps the best looking episode of the bunch thus far, with its other-worldly scenes again delivering in terms of just looking great - it's a real shame that this shallow pleasure is about as much as I can derive from a series that seems to want to do so much more but has alas picked the wrong vehicle with which to do so. In those terms, Black Rock Shooter is the anime equivalent of taking an F1 car to collect the weekly grocery shopping.