A half-hour later dinner is winding down. Laura is still by herself on the living room couch. The floor lamp gives her face "an unearthly prettiness." The rain stops; the lights flicker and go out. Amanda lights candles and asks Jim to check the fuses. There is nothing wrong with them, of course. Amanda sends Jim to the parlor with a candelabra and a little wine to keep Laura company while she and Tom clean up.
In the parlor, Jim's engaging warmth gradually overcomes Laura's shyness and terror at meeting her secret crush after all these years. They sit on the floor and talk. Laura reminds Jim that they knew each other in high school. When she mentions the nickname he gave her, Blue Roses, it all comes back to him. They reminisce about high school and Jim's glories. Laura also remembers her great discomfort and embarrassment, clumping about with the brace on her leg. Jim thinks she was far too self-conscious. Laura learns that Jim never was engaged to his high school girlfriend; the announcement had been "propaganda" on her part.
Laura starts to tell Jim about her glass collection. He abruptly declares that she has an inferiority complex, that she "low-rates" herself. He himself suffered from this condition after his post-high school disappointment. He offers a spate of mid-century pop psychology truisms, then briefly launches into his vision of his own future in television. Laura is rapt. He asks her about herself again, and she describes her collection of glass animals. She shows him her favorite: a unicorn.
Jim notices the music coming from the Paradise Dance Hall across the alley. Despite Laura's initial protests, Jim and Laura dance a clumsy waltz around the room. Jim bumps into the table where the unicorn was resting. It falls and the horn breaks off. Laura says now the unicorn won't feel so freakish. Jim tells her she is different from anyone else he knows. He tells her that she is pretty, that if she were his sister he would teach her to have some self- confidence, help her see her uniqueness. He says that someone ought to kiss her.
He kisses her on the lips. She is dazed, dazzled, glowing. He immediately realizes he has crossed the line and mentally kicks himself for it. He sits next to her on the couch and decides to come clean: he's engaged. Betty is Catholic, Irish, and his steady girl. He calls himself a 'stumblejohn.' Laura places the de-horned unicorn and places it in his hand, as a souvenir.
Amanda whirls into the room with refreshments. Jim is a bit more awkward in her presence now. She insists that he become a frequent caller from now on. He says he must go now. He has to pick up Betty at the train station. The two of them are to be married in June. The sky has fallen on her hopes, but Amanda is gracious in her farewell. Jim cheerily takes his leave.
Amanda calls Tom in from the kitchen. She declares that Tom has played a joke on them. Tom insists he had no idea that Jim was engaged. He heads to the door and another night at the movies. Amanda rails against his selfishness. They shout. She tells him to go to the movies; to the moon, for all he cares about them. He leaves, slamming the door.
Tom delivers his impassioned closing monologue from the fire escape landing as Amanda inaudibly comforts Laura inside the apartment, then withdraws to her room. Tom left the family after being fired from the warehouse (he wrote poems on shoe-box lids). He traveled, drifted, pursuing something he could not identify. Yet he could never leave Laura behind. Everywhere he went, everywhere he still goes, some piece of glass or quality of light brings his sister back to him, to his side. The play ends as Tom implores Laura to blow out her candles, then bids the audience farewell. In the living room, Laura blows the candles out.