In Juliet's famous soliloquy in Act IV she worries:
Laying down her dagger
She fears that Friar's potion will not take effect and that she will have to marry. Just in case, she keeps a dagger close. This foreshadows the suicide to come in Act V.
Then, she worries the Friar is trying to poison her to cover up his involvement in the secret marriage:
What if it be a poison, which the friar
Subtly hath minister'd to have me dead,
Lest in this marriage he should be dishonour'd,
Because he married me before to Romeo?
I fear it is: and yet, methinks, it should not,
For he hath still been tried a holy man.
Then, she fears awaking in the tomb, suffocating with her dead cousin Tybalt.
How if, when I am laid into the tomb,
I wake before the time that Romeo
Come to redeem me? there's a fearful point!
Shall I not, then, be stifled in the vault,
To whose foul mouth no healthsome air breathes in,
And there die strangled ere my Romeo comes?
Alack, alack, is it not like that I,
So early waking, what with loathsome smells,
And shrieks like mandrakes' torn out of the earth,
That living mortals, hearing them, run mad:--
O, if I wake, shall I not be distraught,
Environed with all these hideous fears?
And madly play with my forefather's joints?
And pluck the mangled Tybalt from his shroud?
And, in this rage, with some great kinsman's bone,
As with a club, dash out my desperate brains?
O, look! methinks I see my cousin's ghost
Seeking out Romeo, that did spit his body
Upon a rapier's point: stay, Tybalt, stay!
Romeo, I come! this do I drink to thee.
She thinks she sees Tybalt's ghost and wields a dagger to keep him at bay. Finally, she drinks the potion to quiet her raging mind.
Lady Capulet is so grief stricken that she longs for death:
She wants one thing to easy her mind. Could it be revenge?
Accursed, unhappy, wretched, hateful day!
Most miserable hour that e'er time saw
In lasting labour of his pilgrimage!
But one, poor one, one poor and loving child,
But one thing to rejoice and solace in,
And cruel death hath catch'd it from my sight!
Paris is angry at her death. He says she was murdered:
He will later mourn her death outside the tomb and, as he thinks Romeo is defacing the grave, will avenge her death foolishly. Romeo kills him.
As she contemplates drinking the potion, Juliet of course wants to drink it so as to be able to be with Romeo. At the same time, she is afraid of possible bad consequences. These are:
- The potion could be a poison to cover up Friar Lawrence's complicity in marrying her to Romeo.
- She could awake too soon (before Romeo comes) and suffocate.
- She could be driven crazy by the spirits of her dead ancestors. She sees herself playing with their bones and eventually bashing her own brain in with "some great kinsman's bone."