Emilia experiences her moment of truth in the last act of Othello shortly after Othello has murdered his wife. Othello tells Gratiano
'Tis pitiful; but yet Iago knows
That she with Cassio hath the act of shame
A thousand times committed. Cassio confessed it,
And she did gratify his amorous works
With that recognizance and pledge of love
Which I first gave her. I saw it in his hand.
It was a handkerchief, an antique token
My father gave my mother.
O God! O heavenly God! (V.2)
At this exact moment Emilia realizes why her husband wanted her to give him Desdemona's handkerchief. She plays a pivotal role in Act 5, Scene 2, because she not only knows the whole truth about Iago's villany but she is so devoted to Desdemona that she insists on revealing Iago's treachery to Othello, Gratiano and Montano before she is stabbed by her husband. His act of stabbing her demonstrates his vicious character and serves as tangible proof that she is telling the truth about his machinations. Emilia also realizes in her moment of truth that she is largely responsible for the death of her mistress and that she is married to a most sinister villain.