[1][2][3] After serving three years in the South Pacific, Johnny J. Kilroy and his trouble-making best friend, Pappy Collins, are honorably discharged from the Army and return to their jobs as taxi cab mechanics.

Johnny, who has long been plagued by jokes about "Kilroy," the fictitious American soldier, then finds out that Pappy has been withholding a letter addressed to him, informing him that he has been accepted at Benson College on the G.I.

Although she has promised Pappy to keep Johnny's identity a secret and not reveal any part of their scheme to him, another student, Jimmy White, overhears her talking about him and rushes to tell his fraternity brothers about it.

After a mob of students burns "Kilroy" in effigy, the snobbish members of Delta Omega, led by senior Rodney Meadows, try to force him out of the fraternity by overworking him.

When Rodney and the others discover that Johnny is friends with Pappy and several taxi drivers, they conspire to embarrass him into withdrawing by inviting the underdressed blue collar workers to their pledge dance and then publicly deny that they know the cabbies.

Unknown to Johnny, his conversation with the professor is being broadcast over the lecture hall's public address system, and when the students hear his heartfelt words, they burst into applause and beg him to stay.