I Am Mother, directed by Grant Sputore, isn’t immediately an obvious Girls Underground story but I think it nonetheless qualifies. Since it’s pretty much impossible to talk about this movie without spoilers, the following will contain some.

A girl, known only as Daughter, is raised in an elaborate underground bunker from birth by an android called Mother. Supposedly she is the first of a new race of humans who will be created to replace the now-dead population after some kind of worldwide disaster. She lives in isolation until one day a surviving human woman comes to the door, and Daughter makes the possibly rash decision to let her in, contamination be damned. Except, as she will find out, there is no contamination, and much of what she has been told is a lie – as well as what she is told from here on out, because neither the Woman nor Mother can really be trusted. She struggles to discern which of them is the Adversary, but ultimately it is Mother, and Woman becomes her companion – but one who will betray her with lies. When Daughter finally escapes, she is drawn back to the facility (sans companion) in order to rescue her brand new baby “brother”, a common quest for a GU. Mother tries to win her over but reveals herself to be a much larger Adversary than even expected. In the end, Daughter doesn’t quite “defeat” her Adversary as much as make a convincing appeal that she can go on repopulating the earth without her – and while Mother accepts this, it is also shown to be part of her plan all along.