Suburbia can be a dangerous place. You've got to be careful not to be decked by the shifting winds of gossip or the slippery slopes of nefarious secrets designed to hurt you.

Stephanie Smothers (Anna Kendrick) is raising her young son, Miles (Joshua Satine), on her own. Her husband and half brother were killed in an automobile crash. She is smart but self-denegrating. For kicks, Stephanie is a mommy video blogger, passing on to her small audience things she finds important.

Her orderly and rational life is turned-upside down when she meets Emily (Blake Lively), a stunning, cocky, and sophisticated woman who prances into Stephanie's little world in stiletto shoes. She has a high energy job as a publicist for a top Manhattan fashion designer. She is married to Sean (Henry Golding), a handsome professor. Their son Nicky (Ian Ho) is the same age as Miles.

After she and Emily share some drinks together and trade a few confessions, Stephanie is convinced she has at last found a true friend. She even tries to stop saying "I'm sorry" all the time to please her. That's why she doesn't mind when Emily asks her to pick up Nicky after school as a "simple favor." But when this babysitting goes on for days, and Emily appears to have disappeared, Stephanie begins talking about these developments on her blog.

Paul Feigl directs this spiffy suburban noir filled with plenty of twists and turns. It takes a while to figure out where and why Emily has vanished, giving Stephanie and Sean a chance to play house together. The homemaker turns into a detective as more fascinating details about her friend come to light.

Anna Kendrick's performance is a sustained comic masterwork as she struggles to deal with the changes her new friend has carted into her tidy days. Blake Lively keeps us on our toes as she spreads her anger, disappointment, and neurosis around -- never missing a beat.

A Take-away from A Simple Favor
"Secrets are like margarine — easy to spread, bad for the heart."
from Stephanie's blog