Fiyero has heard that Quadling Country is under militia oppression again and he asks about Elphaba's family there.
Elphaba tells him a lot about her childhood and how hard it was growing up in Quadling Country.
Frex dragged Elphaba around with him on his missionary work, and Elphaba witnessed a lot of political oppression and other "horrors" as a child, as the Quadlings futilely fought against the Wizard's troops:
[Frex] converted [the Quadlings], they went into the struggle with the zeal of the newly chastised. They were dispossessed and disappeared. All with the benefit of unionist grace. (3.6.8)
The Wizard, in the fine tradition of crazy dictators everywhere, has moved on to "disappearing" people by tossing them into jail or forced labor camps. There are definite shades of both Hitler and Stalin (who shipped millions of people off to gulags) here.
Fiyero guesses that Elphaba must not care much about her father. She angrily denies this and says she loves him, faults and all.
Elphaba then talks more about Frex and why he went into missionary work.
Their talk then turns to Nessa. Elphaba hilariously speculates that Nessa will take over as the Eminent Thropp, ruler of Munchkinland, and "she'll be the B---h of the East" (3.6.24).
Elphaba says she didn't want to be Eminent Thropp anyway, so it all works out.