Tom leaves to be free of his responsibilities toward his family--does this plan work for him?
In the conclusion of the play, Tom and Amanda have a furious, and final, argument after which Tom storms out of the apartment for the last time. He leaves his family behind in St. Louis to pursue an independent life of his own. There is evidence in Tom's conversation with Jim O'Connor that evening that Tom had formulated a plan to leave anyway, and it later becomes clear that Tom had used the money to pay the electric bill for other purposes. He had paid his dues to the Merchant Seamen's Union. He actually had taken a step toward leaving.
Tom's moving speech as narrator that provides the conclusion of the drama shows that he left his family but never truly escaped. He has drifted from city to city, ironically living the same kind of life he had lived at home; he smokes, drinks, and goes to the movies to escape that which now pursues him. Tom left his daily responsibilities behind him in St. Louis, but he took the memory of his sister with him, and it is her memory that torments him:
Oh, Laura, Laura, I tried to leave you behind me, but I am more faithful than I intended to be!
Tom understands that he now is trapped in a different way. Nothing will free him from his love for Laura and his sense of betrayal for leaving her. Nothing will "blow [her] candles out," in his mind or in his heart.
The main plot in the drama concerns Amanda's efforts to secure Laura's future, her efforts focusing on the gentleman caller. The subtext of the drama develops Tom's need for independence. This part of the story concludes with his leaving, but in a terribly ironic way.