Hold. Be gone.Be strong and prosperous in this resolve. I'll send a friar with speed to Mantua with my letters to thy lord.
In Act 4.1 Friar Laurence tells Juliet his idea. He knows of a weird potion that will make Juliet appear as if she is dead for "two and forty hours." That's Shakespeare for 42 hours.
Love will give me strength, and strength will help me accomplish this plan. Goodbye, dear Father
In Act 4 .2 Juliet comes home, all fake-humble and repentant. She apologizes for being a bratty teenager and says she'll marry Paris.Lord Capulet is overjoyed and decides the marriage will take place the next day, even if he has to stay up all night making preparations
Why, I am glad on ’t. This is well. Stand up.
Juliet convinces the Nurse and Lady Capulet to leave her alone, then takes out the potion the Friar gave her.
Ay, those attires are best. But, gentle Nurse, I pray thee, leave me to myself tonight, For I have need of many orisons To move the heavens to smile upon my state, Which, well thou know’st, is cross and full of sin.
In Act 4.5 When the Nurse comes to wake Juliet up in the morning, she discovers the girl dead. Then the Friar shows up and takes action, telling them to take Juliet to the tomb, stat.