Based on the novel You Should Have Known by Jean Hanff Korelitz, David E. Kelley‘s six-part mini-series The Undoing is having its premiere on HBO Max. Stars include Nicole Kidman—as a therapist—and Hugh Grant as her husband.
A little background about author Korelitz: her mom is a therapist, who apparently “always brought home cautionary tales to my sister and me about not believing what someone tells you. She went to great pains to get us to understand that just because someone says something doesn’t mean it’s true. We all want to believe that someone is telling the truth – especially if we’re attracted to them” (amny.com).
And thus, as in The Undoing, the main character Grace Reinhart Sachs is a New York shrink whose new nonfiction self-help book is You Already Know: Why Women Fail to Hear What the Men in Their Lives are Telling Them.
Richard Fitzpatrick, Irish Examiner, about this book-within-a-book: “Grace’s thesis is that women delude themselves when picking men. They’re blinded by the need for narrative — to save the man, or that they’re ‘already the heroine and here comes my hero’. They fail to read their self-deception, unwilling to notice the signs that tell them an embezzler, a liar, or a womaniser stands before them.”
Grace herself is in a long-term marriage to Jonathan, a pediatric oncologist; they have a 12-year-old son. From the publisher, additional info: “…(W)eeks before the book is published a chasm opens in her own life: a violent death, a missing husband, and, in the place of a man Grace thought she knew, only an ongoing chain of terrible revelations. Left behind in the wake of a spreading and very public disaster, and horrified by the ways in which she has failed to heed her own advice, Grace must dismantle one life and create another for her child and herself.”
In the first part of the novel readers see how private-school moms live. Then a woman, not someone from her social realm, is found murdered. Publishers Weekly breaks it down further: “Grace, already tense and sad from these events, becomes more and more anxious as Jonathan, at a medical conference in the Midwest, proves unreachable over several days. The author deftly places the reader in Grace’s shoes by exploring her isolation, unease, and contempt for the rumor mill.”
Maureen Corrigan, Washington Post: “It artfully combines wit and suspense into an irresistible domestic nightmare.”
Selected Reviews of The Undoing
Chuck Barney, Mercury News: “Guided by Susanne Bier’s taut direction, the twists keep coming and nothing is quite what it seems.”
David Bianculli, NPR: “I don’t want to give it away. But Nicole Kidman at the center of it all delivers one of the best and most nuanced roles of her entire career.”
Jen Chaney, Vulture: “‘The Undoing’ has the potential to be more substantive than it is, and it’s a little disappointing that it isn’t. Still, it offers a moody sense of atmosphere, a welcome reminder of New York’s pre-pandemic days (the series was shot in 2019), fine acting, and a seductive mystery that will likely lure in even viewers who try to resist it.”

I am very glad that I came across this article. This helped me figure it out.
WARNING: SPOILERS AHEAD!!!
Various articles I read on the series clearly stated that the killer in the book was Jonathan but that the series was going a very different route. Stated in a way that implied not Jonathan.
As a result I counted him out and when the “big reveal” was that it WAS Jonathan, felt like cheap shot. The involvement of Jonathan’s mom was actually creepy to me. She still blames him for the 4 year old daughter’s death. Who leaves a young teenage boy to watch a 4 year old? The mother (or father) needed to step up on that one. Not blame their son and then diagnose him. As a therapist (child psychiatry) I found that especially egregious.