Audrey Wells made a name for herself a few years ago with her screenplay for The Truth About Cats and Dogs, a knowing (if superficial) look at how standards of female beauty undercut the sisterhood. Her directorial debut, Guinevere, is a sensitive (if again superficial) portrait of the dynamic between a sage older artist and the naive young woman who confuses a desire to learn with just plain desire.

The wan young Canadian actress Sarah Polley, who made an impact in The Sweet Hereafter and Go, stars as Harper Sloane, the insecure youngest daughter in a family of well-to-do, mean-spirited lawyers. Instead of entering Harvard, Harper hooks up with her sister's wedding photographer, a doe-eyed, self-possessed Irishman who calls her "Guinevere."

Stephen Rea plays the photographer, Cornelius "Connie" Fitzpatrick, who promises "Guinevere" that he can teach her the secrets of art and life. Harper is smart enough to know that she's living out a clich, but she can't resist the attention--or the feeling that she's finally learning something useful. Even when she learns that she's the latest in a string of "Guineveres," Harper still wants to go where the lesson plan takes her.

For most of Guinevere, Wells keeps us similarly fascinated. How much is Connie's manipulation intentional, and how much is just a result of his own insecurity? Who's using who? But the film's momentum runs out about the same time that its keen observations do. In the final half-hour, Wells drops her amused detachment, and we begin to see Connie and Harper as little more than pathetic losers with nothing real to offer each other (or the audience).

Then there's an abrupt "four year later" coda, in which the "Guineveres" gather for a sort of class reunion. There's an unfortunate smugness to this finale, as Wells stops sharing the attraction and repulsion inherent in a mentor-student romance and instead presents her characters as fully formed products of the experience. The director seems to be saying that the only way to understand this situation is to live through it. The funny thing is, for awhile, thanks to Wells, we were.