In
Gorham, Kansas, circa 1936, itinerant
con man Moses Pray meets nine-year-old Addie Loggins at her mother's graveside service, where the neighbors suspect he is Addie's father. He denies this, but agrees to deliver the orphaned Addie to her aunt's home in
St. Joseph, Missouri. At a local grain mill, Moses convinces the brother of the man who accidentally killed Addie's mother to give him $200 for the newly orphaned Addie. Addie overhears this conversation and, after Moses spends nearly half the money fixing his old
Model A convertible and buying her a train ticket, she demands the money as rightfully hers, whereupon Moses agrees to let Addie travel with him until he has raised back the full $200 to give to her. Thereafter, Moses visits recently widowed women, pretending to have previously sold expensive, personalized Bibles to their deceased husbands, and the widows pay him for the Bibles inscribed with their names. Addie joins the scam, pretending she is his daughter, and exhibits a talent for confidence tricks, such as selling Bibles and the
quick change scam. As time passes, Moses and Addie become a formidable team. One night, Addie and "Moze" (as Addie addresses him) stop at a local carnival, where Moze becomes enthralled with an "exotic dancer" named Miss Trixie Delight and leaves Addie at a photo booth to have her photograph taken alone (of herself sitting on a crescent moon, to suggest the film's title). Much to Addie's chagrin, Moze invites "Miss Trixie"—and her downtrodden teenage maid, Imogene—to join Addie and him. Addie soon becomes friends with Imogene and jealous of Trixie. Imogene reveals that Trixie works, at least occasionally, as a prostitute, and it is suggested she has a venereal disease causing her a frequent need to urinate. When Addie subsequently discovers that Moze has spent their money on a brand-new
Model 48 convertible to impress Miss Trixie, she and Imogene devise a plan. They convince a clerk at the hotel where the group is staying to visit Trixie. Addie then sends Moze up to Trixie's room, where he discovers the clerk and Trixie having sex. Moze promptly leaves Miss Trixie and Imogene behind, with Addie leaving Imogene enough money to pay for her own passage home. While staying at another hotel in a rural area, Moze uncovers a
bootlegger's store full of
whiskey, steals some of it, and sells it back to the bootlegger. Unfortunately, the bootlegger's twin brother is the local sheriff, and he quickly arrests Addie and Moze. Addie hides their money in her hat, steals back the key to their car, and the pair escape. To elude pursuit, they trade their new car for a decrepit
Model T farm truck after Moze beats a
hillbilly, Leroy, in a
"rasslin' match". Moze and Addie make it across the state line to Missouri, where Moze sets up another swindle, only to be caught again by the sheriff and his deputies; outside their jurisdiction and unable to make an arrest, they beat Moze and rob him of his and Addie's savings. Humiliated and defeated, Moze drops Addie at the house of her aunt in St. Joseph, but a disappointed Addie rejoins him on the road. When he refuses her company, she reminds him that he still owes her $200 and points out that his truck has just rolled away without him. They catch the truck and leave together. ==Cast==