Episode 61: Pages 201-219 of volume 4 of the Kodansha publication.
So the Colonel caught up with Chiyoko and is going to help her after all (assuming he can be trusted). Only problem is those rats could've very well infected Chiyoko with something really nasty in that attack. I really don't want to think Chiyoko might be out of the story at some point, she is just way too badass to put down.
Also, it seems Tetsuo is taking Miyako's words to heart and trying to hold off on the drug intake. Imagine if the drugs don't actually inhibit Tetsuo's powers and Miyako only said that so that he put himself under extreme mental distress and be easier to take down later. That's probably not the case, but that would be a clever ruse.