That evening, in the castle hall now doubling as a theater, Hamlet anxiously lectures the players on how to act the parts he has written for them. Polonius shuffles by with Rosencrantz and Guildenstern, and Hamlet dispatches them to hurry the players in their preparations. Horatio enters, and Hamlet, pleased to see him, praises him heartily, expressing his affection for and high opinion of Horatio’s mind and manner, especially Horatio’s qualities of self-control and reserve. Having told Horatio what he learned from the ghost—that Claudius murdered his father—he now asks him to watch Claudius carefully during the play so that they might compare their impressions of his behavior afterward. Horatio agrees, saying that if Claudius shows any signs of guilt, he will detect them.

The trumpets play a Danish march as the audience of lords and ladies begins streaming into the room. Hamlet warns Horatio that he will begin to act strangely. Sure enough, when Claudius asks how he is, his response seems quite insane: “Excellent, i’ faith; of the chameleon’s dish: I eat the air, promise-crammed” (III.ii.84–86). Hamlet asks Polonius about his history as an actor and torments Ophelia with a string of erotic puns.

The players enter and act out a brief, silent version of the play to come called a “dumbshow.” In the dumbshow, a king and queen display their love. The queen leaves the king to sleep, and while he is sleeping, a man murders him by pouring poison into his ear. The murderer tries to seduce the queen, who gradually accepts his advances.

The players begin to enact the play in full, and we learn that the man who kills the king is the king’s nephew. Throughout, Hamlet keeps up a running commentary on the characters and their actions, and continues to tease Ophelia with oblique sexual references. When the murderer pours the poison into the sleeping king’s ear, Claudius rises and cries out for light. Chaos ensues as the play comes to a sudden halt, the torches are lit, and the king flees the room, followed by the audience. When the scene quiets, Hamlet is left alone with Horatio.

Hamlet and Horatio agree that the king’s behavior was telling. Now extremely excited, Hamlet continues to act frantic and scatterbrained, speaking glibly and inventing little poems. Rosencrantz and Guildenstern arrive to tell Hamlet that he is wanted in his mother’s chambers. Rosencrantz asks again about the cause of Hamlet’s “distemper,” and Hamlet angrily accuses the pair of trying to play him as if he were a musical pipe. Polonius enters to escort Hamlet to the queen. Hamlet says he will go to her in a moment and asks for a moment alone. He steels himself to speak to his mother, resolving to be brutally honest with her but not to lose control of himself: “I will speak daggers to her, but use none” (III.ii.366).

In the first two scenes of Act III, Hamlet and Claudius both devise traps to catch one another’s secrets: Claudius spies on Hamlet to discover the true nature of his madness, and Hamlet attempts to “catch the conscience of the king” in the theater (III.i.582). The play-within-a-play tells the story of Gonzago, the duke of Vienna, and his wife, Baptista, who marries his murdering nephew, Lucianus. Hamlet believes that the play is an opportunity to establish a more reliable basis for Claudius’s guilt than the claims of the ghost. Since he has no way of knowing whether to believe a member of the spirit world, he tries to determine whether Claudius is guilty by reading his behavior for signs of a psychological state of guilt.

Although Hamlet exults at the success of his stratagem, interpreting Claudius’s interruption isn’t as simple as it seems. In the first place, Claudius does not react to the dumbshow, which exactly mimics the actions of which the ghost accuses Claudius. Claudius reacts to the play itself, which, unlike the dumbshow, makes it clear that the king is murdered by his nephew. Does Claudius react to being confronted with his own crimes, or to a play about uncle-killing sponsored by his crazy nephew? Or does he simply have indigestion?

Hamlet appears more in control of his own behavior in this scene than in the one before, as shown by his effortless manipulations of Rosencrantz and Guildenstern and his frank conversation with Horatio. He even expresses admiration and affection for Horatio’s calm level-headedness, the lack of which is his own weakest point: “Give me that man / That is not passion’s slave, and I will wear him / In my heart’s core, ay, in my heart of heart, / As I do thee” (III.ii.64–67). In this scene he seems to prove that he is not insane after all, given the effortlessness with which he alternates between wild, erratic behavior and focused, sane behavior. He is excited but coherent during his conversation with Horatio before the play, but as soon as the king and queen enter, he begins to act insane, a sign that he is only pretending. His only questionable behavior in this scene arises in his crude comments to Ophelia, which show him capable of real cruelty. His misogyny has crossed rational bounds, and his every comment is laced with sexual innuendo. For instance, she comments, “You are keen, my lord, you are keen,” complimenting him on his sharp intellect, and he replies, “It would cost you a groaning to take off my edge” (III.ii.227–228). His interchange with Ophelia is a mere prelude to the passionate rage he will unleash on Gertrude in the next scene.