With all of the facilities on her list put out of commission, it seems as if Misaka can finally relax and reflect on a job well done as the Sisters project is surely put out of commission.
With that in mind, even the appearance of old "rival" Kamijou Touma on the scene is a cause for entertainment, as she decides to help him out with a problem with that vending machine. Perhaps the timing of this is unfortunate however, as Kuroko's continued concern about her roommate extends to her discussing the issue with Uiharu and Saten. It's a discussion that leads them to only one conclusion - Misaka has herself a boyfriend. Cue Kuroko running into Touma and Misaka together, putting two and two together and coming up with 4.1 as the answer.
Once this distraction is out of the way, the tone soon turns serious as Touma and Misaka's reverie is interrupted by a visit from one of the Sisters. It doesn't take long for it to emerge that in spite of all Mikoto's efforts the project and its malevolent experiments are continuing apace, leaving Misaka broken and distraught - a feeling not helped as some further research reveals that those in charge of the project have already requisitioned over 180 more facilities to continue the project. As it becomes clear to Misaka that this project is being run with the blessing of those at the top of Academy City, so she begins to plot some extreme measures to put paid to these activities...
In a way, this week's episode of A Certain Scientific Railgun S is really a stop-gap to transition us from one major element of this current story arc to the next - its light-hearted first half was arguably much needed after the high octane events of recent episodes, while the second half is perhaps not the cleanest or most satisfying way to ramp the story back up again but it does the job nonetheless, and sets the scene for a big finish to this story arc which I'm very much looking forward to.