Romeo and Juliet Summary of Act IV, Scene 3
Juliet sends the Nurse and Lady Capulet out of her room. She then considers what might happen if she drinks the potion Friar Laurence has given her. She might not pass for dead, in which case she might have to marry Paris; she might actually die; she might wake in the vault before Romeo gets there and be frightened out of her wits. Steeling her resolve, she drinks the potion and lies down in bed.
In this scene, Juliet’s musings cover all the points the audience expects of the plot to come: her false death, her eventual suicide at knifepoint, and Romeo’s failure to rescue her in time. In her lines about having to share a vault with Tybalt’s corpse lie a double meaning: she fears she will be terrified by Tybalt’s decaying body, but in fact Tybalt’s death has already “killed” both her and Romeo by setting into motion the events that eventually result in their deaths.