: I was very disappointed that a rescue attempt for Leela was never launched in
: M2 or Infinity. She is a heroine of the early battles to defend the
: Marathon and the Tau Ceti colonies, yet she is just cast aside and
: forgotten in the later stories.
But she was also rampant and spread across a vast network. Even if humanity (or anyone, for that matter) tried to "rescue" her, what would they do with her? Rampant AI's are dangerous, and having her back could be a worse prospect than not having her anymore at all.
But if you're referring to before the Vylae purchased her, I think this happened simply because Durandal was the only entity that could have pulled it off but did not, simply because he probably didn't trust Leela, but also because she could not serve as a means to any of his ends.
The Pfhor may have tried to get her back for all we know, but they might not have known who the Nar sold her to after they had stolen her. Plus they had Tycho to play with, and I think its doubtful that Leela would have been very cooperative with the bugs anyway. Then there's always the possibility the Pfhor knew the Vylae had her but because of their relationship didn't wish to forcibly take her, and the Vylae couldn't have given her away if they wanted to, and they probably did want to quite badly.
But who's to say what happened after the war?