So it looks like the confirmation of a third season of A Certain Magical Index was leaked yesterday! Of course I’m over the moon that we’re finally getting this, but I’ve been wondering, what exactly would a third season adapt? Well, I’m here to offer a breakdown of my thoughts to those interested! Keep in mind that this is written by someone who’s read all the light novels, intended for people who’ve at least read all of Old Teastament, so there may be light spoilers from the arc titles, so be warned! I’ll also be using pretty conservative estimates of the minimum amount of episodes required to adapt each arc, so don’t freak out if you feel like I’m not giving an arc enough episodes in my calculations! Fortunately, as you’ll find, there’s a bit of space to work with, so the episode counts could be stretched out to accomodate more content if they choose to. Well with all that said, let’s begin.

How many episodes will it be?

Hard to say. All previous Raildex series’ have been 24 episodes, so it’s not unlikely that Index III will follow that trend. However, it’s worth keeping in mind that the climate of the anime industry has changed quite a bit since then, and 13 episode series’ are becoming much more standard, so everyone should be prepared for that possibility. With that said, let’s look at what content we have to work with in 13 episodes!

Document of Constantine Arc

Battle Royale Arc

Acqua of the Back Arc

I think you’ll find that these three arcs fit pretty neatly into 13 episodes, if we really do end up with 1cour. All three of these arcs take up one volume of the light novel each, but in terms of content density, they vary a little bit. Document of Constantine is absolutely a 3-episode arc, and Acqua of the Back could fit into 3 episodes snugly, or easily take up 4 episodes. Battle Royale Arc, while being only a single volume, is one of the most content-dense volumes in all of Index, with so many plot threads occurring simultaneously. You’ll need at least 5 episodes to do it justice, maybe more. So at the bare minimum, that’s 3+5+3=11 episodes, giving the studio 2 more episodes to dedicate to Battle Royal, Acqua or maybe even an anime-original pilot episode. Or alternatively, if we’re working with 24 episodes, these episodes could be put to use in the remaining half.

SS2

British Royal Family Arc

DRAGON Arc

To address the elephant in the room, I don’t believe there’s any way they’ll be able to fit WW3 into any of these 24-26 episodes. It takes up 3 volumes of the light novel and I believe is the most content-dense arc in all of Raildex, so there’s no way to fit it in without at least 9 episodes / 180 minutes, so don’t expect that just yet. The British Royal Family Arc comprises two volumes of the light novel, and quite a lot happens in them. Dragon Arc is a very humble arc that entirely serves as a prologue to WW3, which would be the perfect place to end the season imo. By my count, DRAGON could be contained in 2 episodes, while the British Royal Family arc would take at least 7 episodes, maybe more to cover it all. Split-cour or not, that gives us a maximum of 4 episodes left to work with, which could either be used to further explore the different arcs, or a couple of them could be thrown in right before British Royal Family to adapt the content of SS2. SS2 is very optional content, but it’s another alternative if they need to pad out the episode count a little.

My speculation is that after the end of these 2 cours, we’ll get WW3 as either a separate 13 episode cour, or maybe even a theatrical release. I can see WW3 selling very well in theatres myself, but I’d personally prefer the extra hour we’d get out of a separate cour, so I’ll be hoping for that.

So, to summarise, here’s my personal prediction about the contents of Index III, just so I can brag if I get it right.

Episodes 1-3: Document of Constantine Arc

Episodes 4-8: Battle Royale Arc

Episodes 9-12: Acqua of the Back Arc

Episodes 13-14: SS2

Episodes 15-22: British Royal Family Arc

Epsiodes 23-24: DRAGON Arc

13-episode Season 4: WW3 Arc

Well, I could keep going. I think the following cour would contain up to and including Baggage City, and the one after that would adapt Ichanaransai and Agitate Halation. But even then, sorry guys, we’ll probably waiting until Season 6 for Othinus, if we ever get that far, which would take up a full cour on it’s own. Following that we have up to the High Priest arc, then up to the Kamisato Rescue arc. By my count, the current contents of the light novels would be at season 7 or 8 of the anime.

Wow, this series really does go on for a while doesn’t it…

Well anyway, let me know if you think I overlooked something in my reasoning! I’d love to hear if any of you have differing thoughts on how this could go down. I’m just really excited that one of my favourite stories is finally getting a continued adaptation. I can safely say that Season 3 will be the best season of Index thus far; you can really see how Kamachi improves as a writer from about Volume 12 onward. We’re finally getting to see the good bits of Index animated. It would be awesome if even more people got into this series as a result!

UPDATE: The community is abuzz as Dengeki Bunko has published a page that seems to be referencing a quote from the WW3 arc. To be honest, it’s left me with an ugly feeling. If it was a movie of a third cour I don’t feel like they’d be talking about it at all this early, so the chances of WW3 being included in our 2-cour Season 3 are regrettably high… SO, time to revise my predictions, and look at how this could work within 24 episodes.

Episodes 1-2: Document of Constantine Arc

Episodes 3-6: Battle Royale Arc

Episodes 7-8: Acqua of the Back Arc

Episodes 9-14: British Royal Family Arc

Epsiodes 15-16: DRAGON Arc

Episodes 17-24: WW3 Arc

It’s definitely not iedeal, but I feel very confident that this is what they’ll go with. If they decide to break the trend and go with 26 episodes, even that would help give them a lot more space to work out the British Royal Family and WW3 arcs. It’ll definitely be squishy, but I can’t help but feel I was a little too optimistic in my original blog here. I still think they can do a decent job adapting the arcs in this amount of episodes. Light novel fans are gonna be mad either way, but I still have faith JC can make it work.

Well, time will resolve all our lingering questions~ October can’t come sooner.