Jim Cassidy, a fallen airline pilot and alcoholic bus driver, is trapped in a volatile marriage with the overbearing, overweight Mildred. One evening at the watering hole where all his drinking buddies hang out, he meets Doris, a wraithlike, destructive rummy. After he goes home with her, he falls for her and begins harboring dreams of starting a new life with her. He gets her to vow to stop drinking and asks Mildred for a divorce. But inevitably Doris, who is haunted by a traumatic past, is unable to stay sober. When his wife’s current beau, with whom he has a running feud, shows up on his bus and starts drinking, he triggers a disaster that drives Cassidy’s life further downward.