Fifteen is the old 18.

The Reader—a surprise Oscar nominee for Best Picture—is a challenging film that bounces between overheated melodrama, historical court drama and, at its best, compelling character piece that spends more energy pondering the mysteries of human behavior on the small scale than on the large scale. It's not the best of the five nominated films, but it's a fine production nonetheless.

In the late 1950s in West Berlin, when ailing 15-year-old Michael Berg (David Kross) has a  chance encounter with a brusquely helpful woman (Kate Winslet) more than twice his age, he can't imagine where it will lead him—into an instructive sexual affair, into love, into the center of a trial with historic implications. Each time they meet, she is instructing him on sexual pleasure and he is, at her request, reading her the classics. He reads, she listens, then she beckons him to make love to her.

"It was said that a new person had appeared on the seafront: a lady with a little dog."

After a torrid time together, Michael's secret lover, who had balked at giving him her name even after they'd been intimate three times, leaves him—a hard, dispassionate worker, she's given a promotion and moves away, leaving him to be a teenager.

Several years later, Michael is in law school and observes a trial taking place involving a group of women accused of being Nazi guards during the war. To his horror, he discovers that one—said to have had a special role of power—is the same Hanna Schmitz he fell in love with, and who broke his heart.

Read it and weep.

The Reader begins as a passionate romance, showering the audience with sensual scenes that leave little to the imagination. Director Stephen Daldry recreates the same feelings Michael must be having, revealing his leading lady's body without shame (how German!) and inviting our scrutiny. But Hanna is no typical swooning sweetheart; instead, she is cold, her approach to life alarmingly workmanlike. When Michael rediscovers her in court, she has become as open as a defendant as she was closed as a lover.

Was she just doing her job in the concentration camp, or was her role special? Is her honesty brutal, or is she an honest brute? Things are learned that leave Michael—and the audience—reeling, and that make the second half of the film feel completely separate from the first.

Years after the outcome, Michael (played as an adult by Ralph Fiennes) will interact with Hanna again. Her enigmatic motives and frank passion are tattooed on his soul, and it's altogether possible that despite some occasionally dodgy old-age makeup, Kate Winslet has created a classic character who will endure as one of the screen's most alluring, frightening female mysteries. Her tough but affectionate nickname for Michael, "Kid," is unforgettable.

Fiennes is wonderfully sensitive in a lightly sketched role, but young Kross is pitch-perfect as virginal Michael and as the slightly older Michael, who will discover he has it within his power to help Hanna even if he may not have it within his spirit to save her from a fate that just may be justice.

I think it would be very tempting to consider the film to be an argument against condemning some of those who participated in the Holocaust; but I felt it was less about the Holocaust than it was about a woman who was the product of her upbringing, whose motivations in life smacked of simple, short-sighted self-preservation, and the warm young man her chilly countenance somehow attracted. At no time did I feel prompted to think, "Oh, that explains her. That excuses her."

I found the film slow-moving, but also felt it ended powerfully, memorably and even intimately. Along the way, I was bowled over by a tantalizingly short pair of appearances by Lena Olin, who plays both an elderly concentration-camp survivor in the 1960s and, 20 years later, her daughter, the author of the book that identified Hanna and led to her trial. A scene between Fiennes and Olin crackles with finality and seemed to underscore all of the preceding film's questions and contradictions.

The end.

I preferred Winslet in Revolutionary Road, but since she is only nominated for The Reader at the Oscars this year, she is the actress to beat. As for The Reader, perhaps it was its pair of recently-departed producers (Anthony Minghella and Sydney Pollack) or its Nazi theme or a savvy marketing campaign by the Weinsteins that got it remembered at Oscar time. But I think Kate Winslet's performance and the film's relentless mining of her character's psyche will make it linger in audiences' minds.