After selecting clothes for the wedding, Juliet asks the Nurse and Lady Capulet to let her spend the night before her wedding alone.
Juliet needs privacy to take her stand against society.
Once they leave, she picks up the vial of potion that Friar Laurence gave her. Suddenly nervous, she thinks about what might go wrong with Friar Laurence's plan: what if the Friar means to murder her to hide his participation in her marriage to Romeo? What if she wakes up in the vault before Romeo arrives, and goes insane because she is surrounded by death and skeletons?
The depth of Juliet's love for Romeo is visible in her willingness to drink the potion despite her profound fears.
Juliet sees a vision of Tybalt chasing Romeo, yet lifts the vial, toasts to Romeo, and drinks.
Juliet's vision symbolizes fate battling love. Juliet, steeled by love, stares down fate and drinks.