If you need to fill a hole in your "Big Little Lies" viewing schedule, get ready for (opens in new tab) "The Undoing," HBO's highly anticipated psycho-thriller about the unraveling of a marriage and the lies built upon it, which, like (opens in new tab) the award-winning "BLL" (opens in new tab) is as (if not more) gripping. HBO has set the first air date for October 25, 2020, but we already have some information on the cast, plot, and original book.

The show has an all-star team both in front of and behind the camera. David E. Kelley, writer of "Big Little Lies," is the writer and showrunner of "The Undoing," and Susanne Bier, who directed the Netflix film "Bird Box" and won an Emmy for AMC's "The Night Manager," directed all six episodes. Kelly, Bier, and lead actress Nicole Kidman served as executive producers of the show.

Kidman, who won an Emmy for Outstanding Lead Actress in a Limited Series for her work on BLL, expressed excitement about re-teaming with Kelly. The actress told Variety (opens in new tab) in 2018, "David has created another propulsive series that centers on a fascinating and complex female role."

Here's what you need to know before "The Undoing" hits streaming services.

"The Undoing" is a six-part limited series based on Jean Hanff Korelitz's 2014 book "You Should Have Known" (though the show deviates from the book's plot relatively quickly). Therapist Grace Fraser realizes that her life is not what she thought it would be after a crime occurs at her son's picturesque private school.

HBO's description of the show reads: "Grace and Jonathan Fraser (Kidman and Hugh Grant) were living the only life they ever wanted. Overnight, their lives crack. Violent deaths, and a chain of horrifying revelations. Left behind in a pervasive and public disaster, and horrified that she did not heed her own advice, Grace must dismantle one life and carve out another for the sake of her child (Noah Jupe) and her family.

The cast of The Undoing is lined with top Hollywood talent. Nicole Kidman plays Upper East Sider Grace Fraser, Hugh Grant charms her charming husband Jonathan, Noah Jupe plays the Fraser's son Henry, and award-winning actor Donald Sutherland is Grace's wealthy and protective father plays Franklin Reinhardt. Other notable cast members include Edgar Ramirez ("The Assassination of Gianni Versace/American Crime Story") as Detective Joe Mendoza, Noma Dumezweni ("The Cursed Child") as attorney Hayley Fitzgerald, Italian actress Elena Alves as Matilda de Angelis.

On August 6, HBO released a trailer for The Undoing. The one-minute clip contains little information about the show's plot, and is punctuated only by the sound of a beating heart.

On September 23, HBO released a longer trailer that provides more clues about the show's plot:

The Undoing will premiere on HBO on Sunday, October 25 at 9 pm. (The series, ordered in 2018, was originally scheduled to premiere in May 2020, but due to COVID-19, HBO delayed its arrival until the fall. Good things will come to those who wait.

Yes, it is. Grant's the best ever, Kidman's a powerhouse, and six episodes just isn't enough.

Variety (open in new tab) writes: "'The Undoing' is very effective as a psychological thriller. But it adds: "Where the film strays is in following the scattershot interests of a plot that keeps twisting." Entertainment Weekly wrote in its review (opens in new tab): "TheUndoing" is beautiful-the people, the locations, the coats. With its directorial missteps, characters' dumb decisions, and dreamy detours, "The Undoing" kept me guessing and, of course, gloating over everyone's misfortunes. And TV Line (open in new tab) describes it as an adrenaline rush: if ultimately not as emotionally complex as "Big Little Lies," it is immediately gripping with its breathless pacing and engaging performances.