With a little over twelve hours left until Index reaches her limit, Stiyl and Kaori leave her and Touma alone until the time comes. Index thinks that her dealing with them will let Touma lead a more normal life, but she soon faints and sleeps for much of the rest of the day. That evening, Touma receives a phone call from Kaori, and she informs him that she and Stiyl are planning on coming back to finish things to match up with the midnight limit. She thinks that he needs time to separate from Index, and she orders him to get it done before they arrive. Refusing to give up, Touma questions if magic can’t help in some way – particularly the 103,000 volumes in Index’s head – but Kaori explains that the Church fears a revolt from Index the most, so she’s not allowed to remember anything related to memory manipulation. What’s more, they see memorizing the magic volumes as a contamination of the brain.
Since Kaori is convinced that magic can’t help, Touma tries to suggest that there could be a scientific solution or a solution using supernatural abilities. Kaori thinks that he’s being reckless, but Touma is determined to save Index. After hanging up the phone, he notices a book about memory manipulation inside Komoe’s apartment. He makes no progress trying to read it, but he does find Komoe’s cell phone bill. Touma decides to try to call her so that she can refer him to a place that does neurological or mental capacity research, but she’s still in the public bath and isn’t picking up her phone. He thus decides to try to call some places on his own, but he isn’t successful and realizes that it’s now midnight. Stiyl and Kaori soon arrive and prepare to kill Index’s memories, and when Touma tries desperately to stop them by suggesting that there has to be another way with all the supernatural abilities and research laboratories out there, Stiyl makes him realize that they don’t have time to hand Index over to strangers.
Stiyl then shows Touma the magic tool that will be used to remove Index’s memory. He gives Touma the option of touching it with his right hand to make it lose its power, but he also makes it clear that what they’re doing is killing Index’s memories to save her life. Stiyl challenges Touma to touch the magic tool if he believes in his own power so much that he’d risk Index’s life, and Touma finds himself unable to do it. However, Kaori convinces Stiyl to give Touma ten minutes alone with Index to say his goodbyes. While the two are gone, Index wakes up and realizes that the mages were there. Touma reassures her that it’s okay and vows to become stronger and save her. Index promises to wait for him before falling asleep again, leaving Touma to cry and curse his own inability to do anything. As he’s doing so though, he recalls what Kaori told him about 85% of Index’s memory being allocated to the 103,000 volumes and 15% of it for everything else. These numbers sound suspicious to him, so he tries calling Komoe again, and this time he gets through.
Touma asks Komoe about Index’s perfect memory ability and specifically if 15% of the brain could be used in one year. Komoe thinks that even with a perfect memory, the brain definitely wouldn’t burst since it can fit 140 years of memories. In order to stress that the human memory isn’t just one thing, she breaks down and explains the different parts of the memory for him, and she concludes by emphasizing that no matter how much knowledge you stuff in your head, it won’t cause so much pressure on your memory that your brain explodes. Knowing now that Index’s perfect memory ability isn’t life threatening, Touma realizes that the Church lied to Kaori and that they tampered with Index’s head so that she’d die if her memories weren’t erased every year. This way, she would never betray them. In trying to figure out what the Church did to Index, Touma decides to use his right arm on her, but nothing happens until he concentrates and touches the symbol inside her throat.
Doing so causes a reaction in her that leads to her body coming alive with her other conscious, and Index prepares to intercept what she considers to be an intruder in order to protect the 103,000 volumes. After some analysis, she invokes something called St. George’s Sanctuary to destroy the intruder. Stiyl and Kaori – who had come running back – can only stare in shock as Touma prepares to face this new challenge.
So, a lot of interesting stuff gets covered this episode: Touma finding out that the church purposefully created the one-year limit so that Index couldn’t betray them, Touma hitting the seal/rune in her mouth, and Index going all possessed/berserk in a very creepy way for a nice cliffhanger. The problem is that all this happens in the final five or so minutes, and the rest of the episode was very slow getting there – heck, Touma pretty much spent half the episode talking on the stupid phone, unable to do anything else and getting annoying in the process. This would probably be one of those times where I’d advocate not following the original material so closely and speed things up a bit. The outlook at least looks good for next week based on the cliffhanger and preview, though I have to say that this shot of Index back to normal is kind of spoiling the fact that Touma succeeds. And who the heck is this guy who somewhat resembles Index?