Jones is Celeste, a successful career gal with perfectionist tendencies engineering the world's happiest separation from Jesse (Adam Samberg), her best friend, perhaps her soul mate, but a man who has simply never grown up.
Jesse is a stock character in romantic comedy, the directionless, less successful, less ambitious man in a lopsided relationship. And Celeste feels familiar as well - she loves her man, but runs out of patience. Practical Celeste stows Jesse in the studio behind their house until the divorce papers are final. Exiled, but handy for cuddling - or comic relief.
Where Jones creates something new is in the intersection of her writing and performance. Something happens to leave Celeste deeply hurt and confused, allowing Jones to add layers of regret, bitterness and second-guessing uncommon to the genre.
But common to broken relationships.
You may determine that Celeste is far too hard on herself here, and she is, but the compulsive self-blame that follows a breakup feel drawn from life, and lend the movie gravity.
Through all of this, the movie retains a light (though R-rated) touch, and is generous to supporting characters - Christian Olsen a local drug dealer, Chris Messina an eager new boyfriend, Ari Graynor her getting-married best girlfriend, Elijah Wood her business partner, Emma Roberts a spoiled pop-star client.
This generosity is something Jones may have developed after playing supporting roles for so long, before she decided the step to the next level with one she could build herself. Good for her.
Contact movie critic Gary Thompson at 215-854-5992 or email@example.com. read his blog, "Keep It Real," at philly.com/keepitreal.