What would you do if your best friend went missing? Stephanie Smothers (Anna Kendrick), single mother and aspiring vlogger, confronts this frightening question when fellow mom Emily Nelson (Blake Lively) calls, asks for Stephanie to babysit, and then disappears.

The search that ensues and the secrets that are uncovered make up director Paul Feig’s “A Simple Favor.”

The film’s greatest asset is Lively. She gives us a captivating performance as Emily, effectively achieving an air of charisma mixed with mystery.

As she asks of Stephanie “just a simple favor,” — even without the weight given to it by the title — we all know that there is something else hiding behind that phrase. The tone that Lively expresses in her role is just dramatic enough to be both fun and enigmatic without being overbearing. However, the same cannot be said for the rest of the movie in its ability to strike such a balance.

Through an onslaught of traumatic flashbacks, emotional vlogs, and passionate lovemaking, things err on the more dramatic side. There is nothing wrong with a film that is heavy or dark, but at times, it seems like “A Simple Favor” cannot decide on its identity.

Serious scenes are followed by moments of flippancy that seem designed for comic relief but often are not timed well or just do not fit the tone of the story. Viewers who see the Prius scene near the movie’s end can decide for themselves whether or not they agree.

All of that being said, “A Simple Favor” has potential if played to its strengths. It is a stylish movie with a fun choice of soundtrack and a cast that doesn’t take itself too seriously. Its plot has some interesting twists, for those who have little hope or faith left in such things. It would have been better presented as either more of a clever comedy or a dark noir. The blend it attempts instead results in a more lackluster movie. Because of that untapped potential, “A Simple Favor” is a 6 out of 10 movie. Those who are not annoyed by melodrama or are perhaps adoring fans of Anna Kendrick will likely give it a higher rating. That does not mean others won’t enjoy it. It will provide some fun, some mystery, and some darkness, but there are other, more smartly made films out there that can do the same.