What plot does Claudius concoct to be rid of Hamlet at the end of the story?

After Hamlet returns from England, Claudius gets Laertes, to challenge Hamlet to a duel. Laertes hates Hamlet because of the death of his father and sister. The sword Claudius gives him is pointed and poisoned, and Claudius doubly assures the prince's death by poisoning a goblet of wine as well.