[The bathroom door is thrown open and Stanley comes out in the brilliant silk pajamas. He grins at her as he knots the tasseled sash about his waist… he stares at her again, his mouth slowly curving into a grin, as he weaves between Blanche and the outer door… The barely audible "blue piano" begins to drum up louder. The sound of it turns into the roar of an approaching locomotive. Blanche crouches, pressing her fists to her ears.]
– Tennessee Williams
A Streetcar Named Desire, Scene 10. These stage directions describe the menacing sexual predator Stanley and a frightened Blanche, just before he rapes her, which is foreshadowed here. His brutish masculinity and evil intent are suggested in the description of him grinning at Blanche in his silk pajamas while he steps between her and the door. The build up of tension is seen in the metaphor of the quiet piano music turning into the roar of an approaching train engine.