"Sibling rivalry" takes on a whole new meaning in this offbeat comedy from first-time writer and director Sue Kramer. Sam (Tom Cavanagh) and his sister, Gray (Heather Graham), are siblings who share a passionate interest in the music and styles of the 1940s, especially movie musicals of the era, and they've earned a powerful reputation on the ballroom-dancing circuit as gifted hoofers with both talent and flair. Sam and Gray cross paths with Charlie (Bridget Moynahan), an attractive woman who shares their enthusiasm for old movies and retro styles, and is a fine dancer to boot. To the surprise of no one, Sam falls head over heels for Charlie, but so does Gray, which comes as a shock to nearly everyone, including Gray, who has never betrayed an attraction to women before. Charlie, however, naïvely fails to acknowledge the depth of Gray's feelings for her as a romantic triangle forms between Charlie and the siblings. Gray Matters also features supporting performances from Sissy Spacek as an analyst, Molly Shannon as one of Gray's co-workers, and Alan Cumming as a taxi driver.