In the play The Birthday Party by Harold Pinter, the interactions between the characters Stanley, Meg, and the mysterious intruders Goldberg and McCann create an atmosphere of tension and ambiguity. Consider how the relationships among these characters reveal themes of power, control, and the fragility of identity. Focus on a specific scene where Stanley's demeanor shifts dramatically in response to the presence of Goldberg and McCann, exploring how this shift reflects his relationship with Meg and the two men.