Laertes
Claudius
SARAH: Laertes exits, and Claudius tells Gertrude that they should follow him and make sure he doesn't do anything rash.
RALPH: You'll remember that it took Claudius a great deal of effort to convince Laertes to settle down and listen to his explanation of what happened to Polonius. Laertes was so upset about his father's death, and the way that Claudius had handled the incident, that when he arrived back in Denmark, he was ready to storm the castle and overthrow Claudius's rule.
SARAH: Claudius is therefore worried that Laertes might return to his rebellious plans. Given that Laertes has popular support in Denmark, this could be dangerous for Claudius's position on the throne.
RALPH: But just as importantly, Claudius is worried that Laertes will forget about their recently made plan to kill Hamlet.
SARAH: Claudius wants Laertes to take care of the "Hamlet problem" in a way that doesn't arouse any public suspicion — and Laertes is continuing to show himself too hotheaded to be trusted.