Please give me a summary of Act III of Othello.

In Act III scene 1, Cassio enters with musicians with the
intention of serenading Othello and Desdemona. A clown tells them that Othello will not
want to hear more music. When the musicians exit, Cassio tells the clown to go and tell
Emilia that he wants to see Desdemona. Iago enters and helps Cassio by getting Emilia
and keeping Othello away. Emilia then enters and tells Cassio that Desdemona and Othello
are discussing what happened between Cassio and
Montano.

Act III scene 2 is a very brief scene where we see
Othello carrying out his role and responsibilities. He gives Iago a letter to deliver to
the senate and Othello, accompanied by gentlemen, walks along the castle
battlements.

Act III scene 3 features the meeting between
Cassio and Desdemona, who tells Cassio she will do what she can to help him. Cassio
leaves as Iago and Othello enter and Iago suggests there was something underhand in
Cassio's body language. Desdemona brings Cassio's case before Othello, who agrees to do
what she wants. Left alone, Iago works more on Othello's jealousy, asking what he knows
about Desdemona and Cassio. Emilia manages to take Desdemona's handkerchief which Iago
then seizes and gives as proof of Desdemona's infidelity, saying that Cassio used it.
Together they plot the death of Cassio.

In Act III scene 4,
Desdemona realises the handkerchief is gone, but Emilia protests she does not know where
it is. When Othello enters and asks for it, she believes Othello is ill. Cassio enters,
pleading yet again for his suit to be resolved, but Desdemona tells him her husband is
not well. She and Emilia go off to find him. Bianca enters complaining that she has not
seen Cassio, and is suspicious about the handkerchief, which Cassio gives
her.