Just when it looked as though our heroes had the upper hand towards the end of To Aru Majutsu no Index II's previous episode, so the tables were turned by a number of Roman Catholic sisters deafening themselves with fountain pens to avoid Index's own unique attack. I have to admit, I flinched at that particular bit of imagery...
Anyhow, with that particular line of defence shattered, Touma and company find themselves on the back foot and holed up inside the church while a bevy of marauding sisters look to force their way inside - probably not the best time to find out that Orsola Acquinas actually doesn't hold the correct key to decipher the Liber Al vel Legis that this whole fuss is about in the first place really.
Despite this revelation that Orsola is of no use to anyone in terms of deciphering this powerful tome, everyone is in too deep to simply go home and pretend it never happened, which brings us to a big face-off between Touma and Agnese, before the former's comrades appear in the nick of time to win the day courtesy of some smart forward-thinking and a little bit of Stiyl's fiery brand of magic. So, Orsola is saved, Touma saves the day despite getting himself injured again, and Kansaki appears to ask his forgiveness for everything that he had to go through as her part in the proceedings to come is confirmed yet further.
To be fair, I found this final episode of this particular story arc to be a pretty entertaining one - despite rendering the entire plot useless on account of Orsola's revelation (or rather, Index's debunking of her supposed knowledge), there were some decent enough set pieces to carry things through no matter how uncomfortable I felt about Touma punching the living daylights out of a small girl. As for this wider story arc as a whole, I'm not really sure where to rate it in the midst of To Aru Majutsu no Index's world - it wasn't terrible but by the same token it didn't grab me hugely, which I guess makes it mediocre at best. Still, it appears as though Kuroko and Misaka return to the fray come the next episode, which is almost a certain sign of improved quality and entertainment value judging by what those characters did for the first season of this series. Bring it on!