In the rural American south, Angel Baby who has been mute from age eight on, is first seen enduring possible date-rape by Hoke. Her mother interrupts and chases Hoke off. Worried about Angel's soul, they go to a tent revival where Paul is preaching. Paul heals her muteness, urging her on to say "God" at first, then "Lord God" and a prayer of thankfulness.
The next day, Angel believes that God has called her, so she decides to follow Paul and work in his ministry. She is given speaking lessons and a great deal of attention. Paul's wife, Sarah, is a bit jealous. Paul's preaching method includes having provocatively costumed women perform the parts of temptresses in the bible, such as Jezebel and Delilah.
Increasingly attracted to Paul, Angel's devotion and passion is cemented when she is attacked by Hoke and rescued by Paul. However, Paul's wife and several other people see the end of the fight and misunderstand Paul's intentions, though it turns out that Paul is in fact in love with Angel.
Angel sets off on her own traveling ministry (with the help of Ben and Molly Hays), but she isn't attracting many followers or many donations.
Noticing her beauty and potential, an unscrupulous businessman, Sam Wilcox, approaches Angel Baby to market his patent medicines. To restore her faith, he hires a few shills in the audience to be healed, despite the warnings of Angel's support team. When they see that the trick has empowered her, they remain silent. They "have a little nip" and head over to Paul and Sarah's to reveal this falsehood.
Paul remains dissatisfied with his marriage to Sarah, because it turns out he was but a choirboy who was led astray by her, molded into a prophet of her imagination. His faith at a low point, he leaves Sarah, ostensibly to go set Angel back on the right path.
Angel has become more and more popular, drawing huge crowds, including Hoke, who vows that he will not stand in line to see her. He and his friends spy Paul approaching the revival tent.
At the front of the tent, there are so many people trying to get in, they are assigned numbers. One man (with a lame leg and 13 children) is particularly bitter about this, yet manages to get in.
Paul tells Angel he wants to marry her (and will be divorcing Sarah). This invigorates Angel's preaching. Meanwhile, Paul confronts Sam who is drinking heavily in the parking lot, telling him he must confess.
Things are going well in the tent, until Sarah bursts in, shouts condemnation of Angel and claims the man in the wheelchair has been paid to fake a miracle. Hoke joins in the fray. The man in the wheelchair freaks out and leaves, which clearly demonstrates the falsehood, and a large fight ensues. As people flee, there is a particularly vivid shot of an upturned wheelchair wheel spinning as the crowd in the background runs around. The tent stars to fall. Sam tries to confess during the middle of the melee, but no one is really listening. Eventually the tent sinks down.
Hoke approaches Angel, who has become mute again. She continues past him as if she can't see or hear him.
Paul emerges from the tent, after removing a large timber that has fallen on his wife.
Angel winds up at a small store, where a husband and wife recognize her and want her to heal their lame son. She turns out not to be mute after all; she tells them that she cannot heal the child. Paul shows up about the same time, and watches as she performs a final miracle; while her faith in herself is destroyed, other people still believe.
The song playing during the closing credits is sung by George Hamilton.George Hamilton as Paul Strand
Mercedes McCambridge as Sarah Strand
Salome Jens as Angel Baby
Burt Reynolds as Hoke Adams
Joan Blondell as Mollie Hays
Henry Jones as Ben Hays
Roger Clark as Sam Wilcox
George Hamilton made Where the Boys Are and was determined to make "better, more serious movies", in part to impress his family of his then-girlfriend Susan Kohner. However, the film was a failure, suffering in comparison to Elmer Gantry. It was shot in Florida.
Reynolds stated, "George Hamilton beat me up in the film, Does that tell you anything?"