Laertes is Polonius's son and Ophelia's brother, a young swordsman who is in France. In Act I, scene 2, he asks the king leave to return there, and before departing he warns Ophelia that the prince's love is passing and that, weighed by his greatness, his will is not his own.
With his father's death, he secretly returns from France and, in Act IV, scene 5, bursts into the castle at the head of a mob that shouts "Laertes shall be king." Before Claudius, he demands: "Give me my father!" He sees his sister gone mad and agrees to hear the king's version.
In scene 7, Claudius tells him that Hamlet killed Polonius and proposes a duel with an unprotected sword. Laertes agrees to be the executor, says he would cut his throat "in church," and he himself adds the poison: "I'll anoint my sword."
In Act V, scene 1, he leaps into Ophelia's grave and fights Hamlet. In the duel in scene 2, he says that attacking is "almost against my conscience," and wounds Hamlet. Then, wounded by his own blade, he says: "I am justly killed with mine own treachery." He accuses the king and asks Hamlet's pardon: "Exchange forgiveness with me, noble Hamlet."