The Undoing is a murder mystery driven by the strangeness of the victim, a young mother, whom we get to know in the first of six episodes. In her scenes with Grace Fraser (Nicole Kidman), she seems to call out for understanding, help, and affection.
Jonathan Fraser, (Hugh Grant), is a suspect because he was the oncologist for the victim's child and had an affair with her. He is arrested and held on $2 million bail. The case seems open and shut, but Grace, Jonathan, and Grace's father (Donald Sutherland,) behave in unexpected ways.
As I write this, I've watched four of the six episodes. The suspects are multiplying and I'm eager to find out who done it, but I'm more eager to find out what would explain the things the victim does in those early scenes. The Undoing generates all the suspense of a traditional murder mystery without sticking to the usual formulas. It puts more emphasis on the characters than on the logistics of how the crime was committed.