When the novel begins, Tom Joad Jr. has served four years of a seven-year sentence and returns to his family’s farm. His conviction was for manslaughter committed in self-defense, not homicide; he was released three years early for good behavior but will remain on parole. Arriving at the Joad farm, he learns that his family has been pushed off by a large company and are living elsewhere. Conversing with the former minister, Jim Casy, Tom acknowledges that he must behave carefully so as not to jeopardize his parole.
When he meets his family the next day, Tom thoughtfully considers their options as they plan their trip to California. He is wary of the uncertain future but wants to support his family, understanding that neither the trip nor the new life as migrant workers will be easy for the older people.
When they get on the road, the risk he is taking becomes more concrete. Once he leaves Oklahoma, he will be in violation of his parole terms. Tom’s decision to do so indicates that he is placing his family before himself. Although he is cross with the gas station owner, he also encourages him to see their shared condition of dispossession. As their trip progresses and the Wilsons join the Joads, Tom acts within the larger group, helping fix the cars; although he is often put out at things such as unfair expenses, he generally controls his temper, knowing that overreacting will endanger the group. Grandpa’s death puts Tom in a different structural position, as his father is now the patriarch and Tom must play a fully adult role.