“A Simple Favor” offers a high-energy romp through an episode in the lives of single mom Stephanie Smothers (Anna Kendrick) and delightfully wicked Emily Nelson (Blake Lively). This well-written, dark comedy moves at a lightening pace with unexpected twists coming fast and furiously. Don’t doze off into your popcorn because you’ll miss an important moment.

The chemistry between actors Anna Kendrick and Blake Lively balances the dynamics of their complicated characters’ relationship. Timing is everything, and they have it perfected. Kendrick has grown up, and her handling of this role demonstrates that fact.

The first introductions of Smothers comes via her video blog for moms where she gives helpful tips on vital elements of daily life – like how to make friendship bracelets or how to ice the perfect cupcake. Smothers always signs up first as a volunteer at young son Mile’s (Joshua Satine) elementary school. By all measures, she’s the quintessential June Cleaver. Then when Miles and his friend Nicky Nelson (Ian Ho) want to schedule a play date, everything changes.

Little Nicky’s mom Emily Nelson is a force to be reckoned with. She smokes; she curses; she drinks gin martinis like they were lemonade. She often disappears for days at a time. In contrast to Smothers, and her stay at home mom status, Nelson works as an executive in the perfume industry. While the boys play, the moms get to know each other.

As they become friends over stronger and stronger martinis, Smothers reveals some dark secrets, but they won’t be as surprising as the ones that Nelson will reveal. Complicated by the presence of her husband Sean Townsend (Henry Golding) and his role, the situation between the two women will escalate when Nelson asks Smothers for that one simple favor.

Elements will start to collide: a funeral, a house fire, a missing person, a terrible car wreck, and really, really strong martinis. Hang on for the ride.

Rated R for sexual content and language throughout, some graphic nude images, drug use and violence.

Marilyn Robitaille writes film reviews for the Stephenville Empire-Tribune and the Glen Rose Reporter.