His family has money problems, the typical sort that plagues lower/middle-class families. Recently, his wife (Vera Miles) has had much dental work, and is afraid that they can't pay off all the bills. Fonda tries to paint the best possible picture of everything..... saying that they always get through the bad times, and that there are a lot of things to be thankful for. In any case, the two agree on going to the insurance company to see if they can take money from the wife's insurance policy. And that's where the trouble begins.
When Fonda arrives at the bank, the teller looks at the approaching man with quiet terror. She goes to the back and tells the others of this man, and they look. Sure enough, they believe that this is the very same man who held up the insurance company a few months earlier. The teller gets all of the pertinent information from the man himself, and soon the cops are at his doorstep, telling him to come to the station. Fonda is flabbergasted at this situation --- he'd never commit such crimes. Yet he finds out the hard way that he will not be able to clear his name at such an early stage -- everybody is convinced that he held up the bank, and other businesses. So he is sent to prison to await trial.
After the husband successfully gets out on bail, the couple get help from a lawyer (Anthony Quayle), who - shocker! - is inexperienced at criminal law (seems that way in all of these movies, doesn't it?). But while the husband later experiences the intensity of the courtroom, the wife experiences an intensity of another kind, as she slowly goes mad. Earlier in the movie, she obviously felt guilty for things she couldn't control, and that guilt complex has manifested itself into something more extreme - she feels at fault somehow for having landed her husband in jail. The subtle implication may be that she unconsciously wonders if perhaps he really is guilty - that he committed these crimes to get money for her, or that perhaps he has a secret life. After all, people who seem a little too normal and steady in their ways have to have some skeletons in their closets, don't they?