"Chris & Don: A Love Story," about the 34-year love between British-born writer Christopher Isherwood and California painter Don Bachardy, begins and ends in states of sunlit happiness tinged with shadow.

The two met on the beach near Santa Monica, Calif., in 1952, when the expatriate writer was 48 and Bachardy was a young-looking 18. It was, Isherwood wrote, "a fated, mutual attraction." But it was complicated -- by the big age difference and by the fact that Isherwood had had an affair with Don's older brother, who suffered from manic depression. Also, one was an established writer and the other a movie-crazed teenager.

Fast forward to 1986, when Isherwood died of prostate cancer in the Santa Monica house where Bachardy still lives. In the six months before Isherwood's death, Bachardy, now a portraitist with a big reputation of his own, dedicated himself not only to caring for his partner, but to drawing him.

The movie recounts these final days as a sort of extended ecstasy for both men. The portraits of Isherwood show a sense of contentment and peace, but also the grimace of pain and the indignity of physical decay.

Critics tend to view Isherwood's literary fame as having peaked in the 1930s, when he joined friend W.H. Auden in Berlin and wrote the fiction that became famous in the musical "Cabaret." But his years in Southern California resulted in his best novel, "A Single Man," and best seller, the sexually frank memoir "Christopher and His Kind."

"Chris & Don" relies heavily on Bachardy, now in his 70s but spry enough to bike everywhere (in Los Angeles!). Isherwood "taught the boy all kinds of wicked things," Bachardy says, laughing. "It was exactly what the boy wanted, and he flourished."

Isherwood put Bachardy through art school and got his famous friends (from Igor Stravinsky to Bette Davis and Fred Astaire) to sit for portraits by the budding artist.

There is wonderful home-movie footage of trips, and some priceless scenes of the couple in Key West, on the movie set of "The Rose Tattoo" with Burt Lancaster and Anna Magnani. Isherwood's reflections are conveyed beautifully in readings from his diaries by actor Michael York. The documentary, written and directed by Guido Santi and Tina Mascara, has the obligatory talking-head experts, somewhat stilted reenactments and too-precious animations of the love bugs' personal cartoon characters (an old horse and a kitty).

There were rocky times in the relationship, as the two struggled with infidelity and jealousy (and social snubbing, especially in the early years). Still, they remained a couple for a remarkably long time, supported each other creatively and basked in the sunshine of each other's love. Now that's a story.

Claude Peck • 612-673-7977