In the near future, Sarah finds out that she has a terminal illness. She has a clone of herself made so her loved ones won't miss her. But when it's discovered that Sarah has recovered completely, it's decided that she and her clone will need to duel to the death - "we can't have two of you walking around - that would be ridiculous."
This reminded me considerably of Yorgos Lanthimos' "The Lobster" for its excessively stylized human interactions, and the way they were usually meta-interactions. Although I get the impression the style can also be compared to director Riley Stearns previous outing, "The Art of Self-Defense" (which I'll now avoid).
I watched this because I like speculative science fiction. I also enjoy SF that uses the future, other societies, and social changes to explore our current social issues. I'm still not sure what this movie thought it was exploring (probably not cloning), but when the writers choose to change human interactions into stilted absurdist dialogue to make some kind of point, or for comedy, they generally lose me. This one sure did. There wasn't a single believable human character in this mess.
Minor Spoiler: To its credit, I had several guesses about where it was headed, and I was wrong about all of them. I guessed that the duel wouldn't take place after the original Sarah spent so much time on training ... I got that right, but I was wrong in all my vague guesses about why. It's good I couldn't guess, but by the time we got to the end I'd given up caring about anything in this unappealing mess.