Describe Iago's revenge against Othello.

Iago hates Othello for passing him over for a promotion in favor of Cassio. With a scheme, he makes Othello jealous of Cassio and distrusting of Desdemona's faithfulness. Othello smothers Desdemona in her bed. Cassio, escaping assassination by Iago, returns with proof of his and Desdemona's innocence. Horrified, Othello falls on his sword and dies.