。
I never dreamed I would see her again.
Literal
Dream [even-in-にも] her [dative-に] again meet-can [quotative-とは] did-not-think.
夢にも (literally 'even in a dream') + negative = 'never in one's wildest dreams.' An emphatic way to deny having imagined something. とは introduces the surprising content with a nuance of astonishment — 'the idea that...'