Nightmare Alley is the sordid tale of a conniving young man who, in the words of one of the film's supporting characters, ends up low because he aimed so high. Drifter Tyrone Power sweet-talks his way into a job as barker for a rundown carnival. He is fascinated by an illegal side-show attraction called "The Geek," a near-lunatic who bites the heads off live chickens and then is "paid off" with a cheap bottle of rotgut and a warm place to sleep it off. Otherwise, Power's attention is focussed on a beautiful if slightly stupid carnival performer (Coleen Gray) who works in an "electricity" act with an equally dense strongman (Mike Mazurki). Power also befriends an alcoholic mentalist (Ian Keith), who demonstrates how easy it is to fool an audience into thinking that his mind reading is genuine. When the mentalist dies after accidentally drinking wood alcohol, Power works his way into the confidence of the performer's widow (Joan Blondell), who teaches Power all the tricks and code words of the mind-reading racket. Power walks out on Blondell in favor of Cathy Downs, who marries him and becomes his partner in a classy nightclub mentalist act. But Power is dissatisfied with show business, and with the help of a beautiful but shifty psychiatrist (Helen Walker) he convinces several wealthy people that he can communicate with their dead loved ones...for a price. One elderly millionaire (Taylor Holmes) offers Power a fortune if he can conjure up the spirit of the millionaire's dead daughter. Power enlists his wife to impersonate the deceased girl, but at the crucial moment she has an attack of conscience and exposes the fraud. His career ruined, Power goes to the crooked psychiatrist for help, but she laughs in his face and calls the cops. He escapes the law by going on the bum, and before long is a drunken derelict. When he approaches a carnival for work, he is told that there is only one job open...as a "geek." When asked if he wants the job, the defeated Power replies "Mister, I was born for it." Based on a lurid bestseller by William Lindsay Gresham, Nightmare Alley was Tyrone Power's attempt to break away from romantic leads in favor of roles with more substance. The picture wasn't a success, but it proved that Power was more than just a pretty face.
by Hal Erickson synopsis