Juliet has summoned up the courage to drink the potion that will fake her death so that she and Romeo can be together.
At first, Juliet’s situation seems hopeless. She is deeply in love with Romeo, but his family is her family’s enemy, and he killed her cousin Tybalt accidentally. She asks Friar Lawrence, Romeo’s mentor, for advice. He finally agrees that since they were married in secret by him, he has to do something. He is good with potions, and knows how to make one that can mimic death. Juliet is pretty enthusiastic about the idea.
Give me, give me! O, tell not me of fear! (Act 4, Scene 1)
Yet when Juliet returns home, pretending she is going to marry Paris and everything is fine, she starts to lose her nerve. She faces down the potion, and suddenly is faced with all kinds of fears.
Her first doubt is that Friar Lawrence set her up, to avoid being found out for his complicity in secretly marrying them.
What if it be a poison which the friar(25)
Subtly hath ministr'd to have me dead,
Lest in this marriage he should be dishonour'd
Because he married me before to Romeo? (Act 4, Scene 3)
Juliet has other fears too. What if she wakes up and suffocates? What if the ghosts, specifically Tybalt’s, turn on her? What if she is so terrified when she wakes up deep inside her family’s tomb that it makes her go mad?
Yet Juliet is driven. Despite all of these fears and doubts, she loves Romeo. She will do anything to be with him. Whatever waits for her, she will do her part. She will take the potion.
Sadly, the plan does not work out. Romeo does not get the message, and goes to the tomb to find Juliet “dead.” He is so distraught that he kills himself, with real poison this time, and then she wakes up. She ends up stabbing herself because he actually is dead.