As another story arc begins (one that's all set to last multiple episodes this time), there seems to be something of a "terrorist" on the loose - Although come the start of the episode that sounds like a rather flattering way of describing them.
In short, the individual in question is capable of remotely accelerating gravitons, something which they are apparently achieving using aluminium. Although all of the incidents come the lion's share of this episode have been decidedly small scale and occurred without injury, the culprit has been fashioning these explosive devices from children's toys and the like, which is an obvious cause for concern.
As Kuroko explains all this to Mikoto, naturally everyone's favourite railgun offers to help - Assistance which Kuroko is only willing to accept after reeling off a long set of promises she expects Mikoto to make, not all of them strictly related to the job in hand. Needless to say, Misaka is none too thrilled by this, but after relating her woes over a parfait to Uihara she ends up thrust into the world of Judgement work anyway on account of Uihara leaving her Judgement arm band behind.
Thus, Mikoto learns that there's more to Judgement work than just catching criminals, as she ends up involved in everything from sweeping up litter to a hunt for a child's missing bag - A hunt which of course she mistakes as being associated with those aforementioned explosions, but which turns out to be nothing of the sort. That isn't to say that the terrorist incidents have been forgotten however, far from it - That's one for next episode....
Although this instalment certainly flattered to deceive by offering up a potentially juicy storyline only to defer it until the next episode, it nonetheless managed to continue To Aru Kagaku no Railgun's ability to serve up instalments which are consistently fun to watch without fail. There was nothing unique or incredibly noteworthy here, yet the interactions between Mikoto and Kuroko in particular, and indeed between all of the characters, kept things both interesting and amusing throughout, while of course we're now very nicely set up for some more dramatic fare in episode seven.