After Mr. Stiles's truck is stolen from Eddie while he stops over at his apartment in southeast Fresno, it is evident that Eddie cannot make it living in his old neighborhood and must eventually leave. He is plagued by bad luck, antagonist "cholos," his family and his own bad judgement. He tries taking vocational classes at Fresno City College but finds that air conditioning repair leaves him bored. He reveals that college was just like high school, the teachers uninspiring and the students apathetic.
He tries to be industrious and goes to work painting numbers on curbsides in the wealthier section of north Fresno. When he is hired by Mr. Stiles, things seem to be working out. Mr. Stiles even trusts him with his truck to take gardening waste to the dump. Eddie, feeling good about himself, foolishly stops at his apartment to get a drink of water and change clothes when the truck is stolen, presumably by gang members who are ubiquitous in Eddie's poverty ridden neighborhood.
Even his family is no help to Eddie. His tía (aunt) is hot for Eddie to go after her son's killer and presents Eddie with a gun to do the deed. He doesn't take the gun but is later approached by Angel, who has taken the gun and wants Eddie to help him get the guy with the "yellow shoes" who supposedly killed Jesús. When he refuses to help Angel he cannot escape the idea that Angel is out to get him. Eventually Eddie has a running brawl with Angel which prompts him to join the Navy and get out of town.
In the final lines of the book the bus which will take Eddie to training camp has stopped near an agricultural field. In the field, the symbolic onions of the novel's title make Eddie cry, but this time he indicates these will be the last tears of his childhood. By leaving Fresno he has hopefully overcome the dead end life he has known since childhood.