I don't have a name for the thing that happened to me, but I don't feel safe any more. (p. 17)
Dana finds herself thrown back in time to 1815, to encounter a distant ancestor Rufus, whose life she seems destined to save over and over again. Because otherwise what will become of her?
Simple premise, vastly complicated by the fact that Dana is Black and Rufus is white, the son of a Southern plantation-owner; that Dana is a modern woman (though for 'modern' read '1976', which feels like a very long time ago when one reads a novel set partly in, and written in, the mid-Seventies) and Rufus is a racist, sexist, elitist product of his time. That Dana's husband Kevin is white, too, and when he time-travels he ends up complicit in her oppression, becoming increasingly like the white men who represent all that Dana is not.
And Dana herself finds she's increasingly a part of the violent, unjust past: that every day she's less an observer, more accepting, another step closer to being what any Black woman in the South must be, a slave, a less-than-human. Every day she has more respect for her Black ancestors and their powers of endurance, their strength. Butler's depiction of Dana's emotional journey -- very much shown, not told -- is masterful: the reader understands more of Dana's situation than anyone in the novel.
Dana's very much a victim of apparently-random weirdness: there is no objective reason for the time-travel, and none (except ... justice? punishment?) for what she suffers on her return from her last trip. Has she changed the past? It's certainly changed her.
Compelling, disturbing, powerfully-written: I understand why it's a classic.