Like many I suspect, I sit firmly in the "To Aru Kagaku no Railgun is better than To Aru Majutsu no Index" camp (not that I dislike the latter), so the chance to watch another episode of this fantastic female foursome is always quite alright in my book - enter this EX OVA which attempts to deliver.
This one-shot episode enters the fray after all of the events of the main series itself, finding Misaka as somewhat the centre of attention as a heroine of Academy City, although as ever she seems to be equally adept at getting herself into scrapes thanks to her short temper. Still, even her steely nerves are jangled as she feels what seems like someone's stare boring into her back after one particular incident - a discomfort not helped by Saten's discussion of an urban legend doing the rounds about someone going around watching people; not an unusual feeling in a society where surveillance is rife, mind you.
Urban legend or not things only get worse for Mikoto as she becomes more and more disturbed and paranoid by this feeling that someone is close by; a paranoia that understandably worries her friends. While we're treated to delights such as an inevitable bathhouse scene, Kuroko and Uihara are hard at work tracking down leads and piecing together what they increasingly believe to be a genuine threat that Misaka has picked up on. This leads us into a final ten minutes where the villain of the piece and their motivations are revealed, followed by a short chase sequences before they're caught and the day is saved, even if Kuroko's victory for the day appears to be somewhat short-lived...
Ultimately, this is everything you'd probably expect from an OVA - a little fan service and some pandering to the desires of fans overall, sandwiched into what is actually a pretty solid story that would have sat quite happily within the main series itself. More time could arguably have been spent both building up to and then apprehending the story's criminal to match up with this interesting story, as revealing her motivation in particular was incredibly brief, but I suppose that's only to be expected from a one-off episode like this. Still, there's plenty here for To Aru Kagaku no Railgun fans to enjoy and revel in, and let's face it - that's entirely the point of this episode.