Will there be a second season of The Undoing?

The prolific showrunner himself refused to rule out the possibility of future episodes in a recent interview, but did admit that he was "satisfied" with how season one concluded.

Nevertheless, a recent Instagram post from star Nicole Kidman has stoked up yet more speculation of a follow-up (more on that below) and strong viewership will certainly help move such a project along.

The Undoing is on track to be the biggest ever launch for a US drama on Sky Atlantic, impressively beating out competition from the likes of fantasy epic Game of Thrones and comic book drama Watchmen.

Read on for everything we know so far about a potential second season.

(Spoilers for season one follow).

Will there be a season 2 of The Undoing?

At the moment, it's uncertain whether The Undoing will return for season two, despite its critical and commercial success.

The first season is a complete adaptation of the novel You Should Have Known by author Jean Hanff Korelitz, meaning there is no source material on which to base a follow-up.

That's not necessarily a deal-breaker, but it should be noted that HBO has billed The Undoing as a limited series (i.e. intended to run for only a single season), which suggests they are not currently considering a second run.

However, the same was true of Big Little Lies when it first premiered and that show went on to secure a season two renewal, with a third also rumoured to be on the way - so never say never.

Nicole Kidman sparked speculation of a follow-up in a recent Instagram post, where she thanked the cast and crew of The Undoing, adding: "Greatly looking forward to working with all of you again."

Fans took to the comments to ask whether that was a hint that they would be reuniting for a second season, but there's no confirmation just yet.

What could happen in a second season of The Undoing?

If The Undoing did return for a second season, there would certainly be plenty of ground to cover in terms of story.

The Undoing ending revealed that Jonathan was behind the brutal murder of Elena Alves, but justice was served as his defence in court fell apart and police closed in on him.

Still, both Grace and her teenage son, Henry, will be feeling traumatised by the ordeal he put them through, so season two could focus on how they go about rebuilding their lives and healing from the damage he has caused.

It would also be interesting to see whether they decide to have a clean break from Jonathan or if he remains a part of their life from prison.

Who could be in the cast for a potential second season?

If The Undoing were to return for a second season, HBO would likely want Nicole Kidman and Hugh Grant to reprise their roles, as their A-list status was a major boon to the first series.

Assuming the focus would remain on the Fraser family, we could also see the return of Donald Sutherland and Noah Jupe, as grandfather Franklin and teenage son Henry respectively.

The Undoing is available to stream on NOW TV. You Should Have Known is available to purchase on Amazon. Looking for something else to watch? Check out our TV Guide.