New York city girl Evie O'Connor works as a secretary for the Trojan Shirt Co. in Brooklyn. She has her mind set on finding a tall, strong man to marry - one that can wear a Trojan shirt with a 16 1/2 neck size.
She writes a short letter and puts it in a shirt that is to be sent to an army camp. The shirt eventually ends up on private Edgar "Wolf" Larsen, who has quite a reputation as a ladies' man. Wolf reads the letter aloud to his bunk mate John Phoneas McPherson, then throws it away. John picks it up again and gets interested in finding the woman behind the letter. Although not as tall and strong as Wolf, John decides to pursue Evie by writing her back.
John and Evie become pen pals, but he sends her a picture of Wolf when she asks for a picture of him, since he is afraid she will lose interest if he admits to not being of the same size and dimension.
Some time later John's unit passes through New York, and he goes to see her, posing as his own friend Wolf. When he sees her he is smitten at the first glance. Still, he continues to pretend being someone else. Wolf finds out about the correspondence between him and Evie, and makes a surprise visit at Evie's place when John is there.
A commotion occurs as John tries to stop Evie and Wolf from being alone with each other, and at the same time fending off Evie's roommate Barney Lee, who is attracted to him. He eventually pretends to be drunk and forces Wolf and Evie apart.
Jealous, John strikes Wolf outside Evie's apartment and tells him to stay away from "his" girl. Wolf ignores John's command and meets Evie again in secret. John finds out about their meetings when Wolf answers her phone.
John rushes to Evie's apartment building and starts a fire to smoke the couple out. In the ensuing commotion, Wolf trips and falls, hurting his head. Subsequently, when not in his right mind, Wolf asks Evie to marry him. She accepts, but the marriage is postponed, since the unit is shipped overseas the next morning.
While away in Europe, Wolf meets and marries a French girl. John keeps writing letters to Evie, still pretending to be Wolf. She eventually finds out about his deceit and ends all contact with him.
After the mission in Europe is over, John comes home and decides to pay Evie a visit. She is not very happy to see him, but after a while she changes her mind, keeping in mind their correspondence over time, and realizes that she loves him. She confesses to knowing that it was he who wrote her all along, and they unite in a kiss.Marsha Hunt as Evie O'Connor
John Carroll as Edgar 'Wolf' Larson
Hume Cronyn as John Phineas McPherson
Spring Byington as Mrs. McPherson
Pamela Britton as Barney Lee
Norman Lloyd as DeWitt Pynchon
Percival Vivian as Mr. McPherson
Donald Curtis as Capt. Budlowe
Esther Howard as Mrs. Edgewaters
Robin Raymond as Eloise Edgewaters
Therese Lyon as Mrs. Jackson
Lynn Whitney as Miss Jenkins