Emily is frustrated by the lack of success of her husband, English professor Sean Townsend, and their (well-hidden) poor financial situation.

Detective Summerville reports that Emily lied about Miami, and that her drowned body was discovered in the lake at a summer camp in Michigan.

Summerville reveals to Stephanie that Emily had severe liver damage, a large amount of heroin in her system, and that Sean had recently taken out a $4 million life insurance policy on her.

Her information leads Stephanie to a yearbook that shows Emily to be a girl named Hope McLanden, who had triplet sisters Faith and Charity.

Stephanie visits their mother Margaret, who explains that at 16, Faith and Hope had set fire to the family house, killing their abusive father, and disappeared.

While Stephanie is away on her investigative trips, Emily surprises Sean by reappearing, telling him that she plans to collect the insurance money and leave the country.

Stephanie has a change of heart and stages an argument with Sean in front of Emily in order to incriminate her while police-planted microphones are recording the meeting.

In January 2016, it was announced that 20th Century Fox had bought the film rights to author Darcey Bell's novel A Simple Favor prior to the book's publication.

[6] Linda Cardellini was announced as having been cast in an undisclosed role in September 2017,[7] and Andrew Rannells, Jean Smart, and Rupert Friend were later added.

[3] In the United States and Canada, it was released alongside White Boy Rick, Unbroken: Path to Redemption and The Predator, and was projected to gross $12–15 million from 3,102 theaters in its opening weekend.

The website's critics consensus reads, "Twisty, twisted, and above all simply fun, A Simple Favor casts a stylish mommy noir spell strengthened by potent performances from Anna Kendrick and Blake Lively.

[2] Amy Nicholson of Variety wrote: "The film feels a lot like the Serge Gainsbourg number that Stephanie dances to in the kitchen: jazzy, a little sleazy, and worth a cult following.

[18][19] In March 2024, Amazon officially greenlit the sequel, with Golding, Rannells, Salahuddin, Satine, Ho and McCormack also reprising their roles.

[20] The sequel, Another Simple Favor, is set to premiere at South by Southwest on March 7, 2025, followed by its release on Amazon Prime Video on May 1.