Misaka's character is very well demonstrated through this story, showing how her racing mind is always worried about perceptions pertaining to her, both tangible and intangible. It becomes a physical impairment which is followed through with successive scenes of very cool transitions through time, coupled with paranoia and steadily deduced problem solving. Sure, the ending is conjured from nothing, but the general tone of the series is kept throughout the ride.
The character interactions are at their best here without being crammed in like many other short specials. It reflects on the series so well without just retelling events which already happened, a problem which Index ran into at the end of its first season. Really though, I like it mainly because it plays with the concepts of esper powers in a way that the series should really strive for. There were great scenes of Misaka's utilization of it and though the special has some extra length, it never feels like it's plodding along to nowhere.
This episode can really be watched at any time, though after Season 1 would be preferable, due to some very minor references to past events. If the rest of the show maintained this standard all the time, it would be the truly interesting shonen it's got the potential to be.
