'A Simple Favor' Teaser Asks "What Happened to Emily?"

The upcoming thriller, directed by Paul Feig, stars Blake Lively and Anna Kendrick.

A Simple Favor stars Anna Kendrick and Blake Lively as two best friends in a small town. But it turns out Kendrick's character, a mommy vlogger named Stephanie, might not know Lively's Emily as well as she thought. 

The new teaser trailer for the film, directed by Paul Feig (Bridesmaids), shows Stephanie admiring the mysterious and elegant Emily. When Emily goes missing, Stephanie has to put the pieces together herself. Photos of the women fall together, begging the question "What happened to Emily?" 

"She is an enigma, my wife," Henry Golding's character, Sean, says of Emily in the trailer. "When you're close to her, you never quite reach her."

A Simple Favor follows Sean and Stephanie as they attempt to uncover the secrets, twists and revelations Emily has left behind. The movie is adapted from a book of the same name by Darcey Bell. Linda Cardellini (who starred in Feig's Freaks and Geeks), Eric Johnson (Fifty Shades Darker), Jean Smart (Legion), Rupert Friend (Homeland) and Andrew Rannells (Book of Mormon) also appear in the film. 

The movie will hit theaters Sept. 14.