In Pittsburgh, Pennsylvania, Dominick Luciano works as a garbage collector to pay medical school expenses for his twin brother, Eugene. While working at the hospital, Eugene learns he has been accepted into a residency program at Stanford University in California. However, Eugene feels unable to leave Dominick, who became intellectually challenged after suffering brain damage in a childhood accident. As Dominick works his garbage route, co-worker Larry Higgins insists that Eugene does not appreciate Dominick and will one day leave. However, Dominick assures Larry that his brother would never abandon him. As Larry Higgins collects trash, Dominick chats about comic books with Mikey Chernak, a young boy on their route. Meanwhile, Eugene begins tutoring fellow medical student Jennifer Reston. Eugene eventually falls in love with Jennifer and introduces her to Dominick. Jennifer asks Eugene if Dominick will go to California with him, but Eugene admits he wants to move by himself. Later, Dominick gets ready to celebrate their birthday, but Eugene telephones from the hospital and cancels. Disappointed, Larry Higgins invites Dominick to see Mrs. Vinson, a lonely housewife. Larry encourages Dominick to sleep with her, but he declines. Across the street, he sees Mikey Chernak sporting a black eye. When Mikey claims to have fallen, his father, Martin, yells at Mikey to come inside. Afterward, Larry and Dominick go to a bar. Telephoning the hospital, Dominick learns that Eugene left for the evening with Jennifer. Upset, Dominick gets drunk with Larry. Arriving home, Dominick finds Eugene and Jennifer. Jealous, Dominick reminds his brother that he pays his way through school. Frustrated, Eugene loses his temper and pushes Dominick. In the morning, Eugene takes Dominick and his dog, Fred, out into the country for have a picnic. After Eugene confesses he will be moving to California without Dominick, Fred runs into the street and is killed by an automobile. Later, as Dominick collects the garbage from Mikey Chernak’s house, he sees Martin ordering Mikey to the basement. When Mikey refuses, Martin pushes him down the stairs. Martin realizes Mikey is severely injured and calls an ambulance. Worried about Mikey, Dominick goes to the hospital. However, Martin informs him that Mikey died from the fall, and threatens Dominick not to tell anyone he pushed him. Later, Dominick fears Martin will hurt Mikey’s baby brother, Joey. Taking a gun stored in the garbage truck, Dominick goes to the Chernaks and takes the baby away for safe keeping. Martin Chernak calls police and Dominick is found hiding at an abandoned warehouse. Assuring officers Dominick is not dangerous, Eugene goes inside. Dominick admits that watching Martin push Mikey triggered the memory of their father repeatedly beating him. When he asks Eugene why he never told him the truth about how he hit his head, Eugene confesses that Dominick had been protecting him from their father at the time he received his injuries. Dominick forgives Eugene, and they leave the building with the baby. Martin appears with a gun and fires at Dominick, but Eugene tackles him. Afterward, Dominick tells police about Mikey, and Martin is arrested. Later, Eugene prepares for his move to California. Dominick gives him a photograph of himself, and assures his brother he will be all right on his own.