Finally freed from his captivity at the hands of Senjougahara, thanks in no small part to Hanekawa, Koyomi finally gets the chance to return and aid his sisters after Tsukihi's plea for help received to his mobile phone.
The trouble is, do the Fire Sisters really want their big brother's help? It certainly doesn't seem like it as they refuse to tell him anything about what's doing on, much to his irritation. Luckily, Tsubasa's presence and her apparent assistance with whatever Karen and Tsukihi have been up to gives our protagonist a chance to find out at least a little of what's developed here - a story which unsurprisingly involves the Fire Sister's attempts to track down the peddler of curses which affected Nadeko and others at their school, and even less surprisingly led them to Deishu Kaiki.
As Araragi goes for a bath to cool off and mull over whether there's really any danger from a supposed swindler like Kaiki, so a wild Shinobu appears - not just to tease Koyomi in terms of both body and mind as she proves surprisingly talkative, but also to offer her own thoughts on the situation, even if she's at pains to announce that this is on account of her boredom rather than any true desire to help. Recounting a story she heard from Oshino, it seems that Karen has been afflicted with a cursed disease known as the "wreathe-fire bee", a rampant fever that sure enough has now struck Karen down. That, of course, leaves the question of what to do about it - Shinobu is unable to help with any simple resolution in this case, which means that Koyomi is likely going to have to take far more direct action to save his little sister.
After all the japes and joking around of its early episodes, things have finally taken a more serious turn as of the latter half of this week's episode of Nisemonogatari, although this series being what it is even the most worrying of situations are served up with playful banter between characters, in particular as we finally get a proper introduction to the formerly mute Shinobu as she toys with her "master" while also filling him in on the gaps in his knowledge. This makes for another dialogue filled, visually stunning, frequently perverted and generally engaging instalment - yet there's still an indefinable something missing in comparison to Bakemonogatari. I can't quite put a finger on what that something is, but it continues to nag at me as the series goes on, somewhat akin to an worry that the series is trying too hard to appease the fans and losing some of the heart of what made its predecessor great in the process. I don't want to say that I'm not enjoying this series, because that wouldn't even be vaguely true, but somehow I feel it's leaving a gap in my heart that I can't quite grasp.