Director Dylan Kidd’s Roger Dodger was an urban comedy of masculine swagger, exceptional sex drive and cynical charge. In the unexpectedly surprising P.S., he turns the tables and presents the most well-rounded and complex American female movie character in any film this year. Based on the novel by Helen Schulman, it’s a moving story of disillusionment and second chances.

Laura Linney stars powerfully as a thirty-nine-year-old, bitter college admissions advisor who becomes convinced that a young applicant is the reincarnation or reappearance of her high school boyfriend, who died decades earlier. Rather than use the device to it’s obvious fantastical ends, director Kidd shrewdly employs it to deconstruct and repair a series of failed relationships.

Louise Harrington (Linney) is approaching 40, counting calories and divorced. Colleague and ex-husband Peter (Gabriel Byrne) has met someone new. Competitive best friend Missy (Marcia Gay Harden) is married and on the make. Louise has strained familial relationships with her doting mother (Lois Smith) and ex coke-head brother (Paul Rudd), twelve-stepping his way to a better life. She’s stuck in a routine of sameness, numbness.

Then something big happens: new Columbia University applicant F. Scott Reinstadt (Topher Grace), a dead-ringer for her high school boyfriend who died over two decades ago, ends up in her office. He uses the same expressions. He paints the same pictures. He has the same name. The two fall immediately in love. Has her one true love returned? Is it all just coincidence?

Director Kidd’s film is unabashedly romantic and the two leads are electric together, particularly in their intense lovemaking scenes and richly written confrontations, where Louise tries to come to terms with her cynicism, age and life experience that counter F. Scott’s youthful ideal romanticism.

The film, however, is not content to strictly focus on the mystical premise. What Kidd is really getting at is how Louise flowers under the possibility of love—forcing her to examine her crumbling relationships with nearly everyone in her life. Byrne, Harden and Rudd all perform excellent dramatic scenes rich in anger, regret and confession. Pro Linney listens, reacts, contemplates and then, in a stellar exchange, tears into Grace about the problem with people in life ‘moving on’ too frequently.

The relationship between the two women, and acting matches between a cerebral Linney and a physical Harden (whose flamboyance is at once charismatic and a tad humbling), is at least as complex, if not more, than between Linney and Grace. When was the last time you saw a female character in an American film who's this developed and interesting on both personal and professional levels -- daughter, sister, best friend, ex-wife, lover, possibly failed artist? Linney does it all here. She’s alternately angry, astonished, disillusioned, in love, confused, jealous, at peace. Possibly her best moment comes in a small scene set in a pool-hall restaurant where Grace says exactly the right thing to her at the right moment.

P.S. is many things—romantic, bittersweet, hopeful. It’s also one of the year’s essentials.