What happens when Gone Girl is crossed with Nancy Drew? You get A Simple Favor a tonally uneven comedy thriller.

A Simple Favor’s story has two quirky leading ladies who reside in a sleepy suburbia. The first one is a young widow, aptly named Stephanie Smothers (Anna Kendrick), a mother to a peppy boy named Miles (Joshua Satine) who is a stay-at-home mom who runs a vlog channel that gives out recipes and tips for mothers. The second one is Stephanie’s polar opposite – an androgynous fashionista named Emily (Blake Lively) with a curt, sharp tongue. Emily is married to a handsome professor named Sean (Henry Golding), a once successful writer, with whom she has a son, Nicky (Ian Ho) – seemingly the only person she holds dear.

Miles and Nicky are friends from school, and when the question of a playdate pops up, the mother come face to face. Stephanie is immediately stunned by Emily, who wears a tailored suit with detachable collar and cuffs, and soon enough is more dizzied by Emily’s lifestyle (she drinks martini during day time) her modern home (it also has a nude painting of Emily hanging in the living-room) and her job (she is PR executive at a big designer label in Manhattan).

Both of the ladies instantly gravitate towards an awkward friendship that teasingly tips towards something more, when Emily disappears after asking Stephanie to pick up Nicky from school and take care of him till she comes back. Sean can’t make it as he is in England taking care of his ill mother.

Stephanie, being a good friend takes care of Nicky, but after two days and no word from Emily, she contacts Sean. The rest of the film is a clumsy thriller, which has its moments of chuckle. Mostly though, it lulls down and loses its grip on the plot then choppily stuffs in for a big reveal of crosses and double crosses.

Lively and Kendrick makes the movie come alive. Lively is fantastic as the femme fatale that could do anything to suit her whims while smiling coldly; beneath the cold aloof exterior, she turns out to be more scarred then she lets on. Kendrick has the doormat mentality projecting from her over-volunteering suburban nature, but like Lively has some darkness of her own. Golding is the certifiable new smoldering heartthrob with an air of genuine liability to him. All of them hold the movie through.

Feig who has done a line of women-lead comedies, missed a great opportunity with A Simple Favor in executing a genuinely eccentric comedy thriller.

Still, A Simple Favor is worth one’s time of day because of its cast. It’s also fun – that is, until the fun starts deflating as the mystery deepens.•