Cal Gant is in jail because of Gretchen Lutterman and her dad, who wants to kill him. Jail is not a place Cal thought he’d ever be, but he is relieved that he finally feels safe in prison. Moving back in time, Cal tells how he wound up behind bars.

In his recounting, Cal is a senior at Central High School in St. Paul, Minnesota. His family isn’t wealthy but they do “all right,” with Horace Gant, Cal’s dad, driving a streetcar for the Twin Cities Rapid Transit Company.

One of Cal’s best friends is Steve Holland, who discovered he had polio in the sixth grade, making his right leg skinnier and shorter than his left leg. Steve limps, and due to his physical condition, the only position and sport he can play is a hockey goalie. Jerry Douglas is another one of Cal’s best friends. They like to punch each other’s arms as a friendly gesture.

The plot begins in Miss Whalmen’s study hall in Cal’s high school auditorium. Jerry gives marbles to the other students to play a prank on the teacher. At 1:20 pm, everyone drops their marbles, startling Miss Whalmen.