BDSM is the incredible odyssey of Zack Simms--a burnt-out 44-year old cab driver who leads a double life. In the daylight hours, he is your average working stiff-an overworked and self-medicating alcoholic who's married to a beautiful and devoted woman; at night, he becomes an insatiable fiend to a powerful dominatrix named Sadie Sunshine. The tall, striking, severely depressed woman becomes the desperately needed lubricant for Zack's stiff existence. Her amazing skills-and her machines-frees Zack's inhibitions; she thaws his numbed body to strange and uncontrollable urges, where both pleasure and violence dissolve into one.