Something is amiss in Denmark -- for two successive nights, the midnight guard has witnessed the appearance of the ghost of Old Hamlet, the former King of Denmark who has recently died. The guards bring Horatio, a learned scholar and friend of Hamlet, Prince of Denmark, to witness this apparition. Though skeptical at first, Horatio sees the ghost and decides to report its appearance to Hamlet.
Meanwhile, a new king of Denmark has been crowned: Claudius, Old Hamlet's brother. Claudius has taken Old Hamlet's widow, Gertrude, as his wife. We watch their marriage celebration and hear about a threat from the Prince of Norway, Fortinbras, which Claudius manages to avoid by diplomacy. Hamlet is in attendance at this wedding celebration; he is hardly in joyous spirits, however. He is disgusted by his mother's decision to marry Claudius so soon after his father's demise. Horatio tells Hamlet of the appearance of the ghost and Hamlet determines to visit the spirit himself.
Meanwhile, the court adviser, Polonius, sends his son, Laertes, back to Paris, where he is living. Laertes and Polonius both question Ophelia (sister and daughter, respectively) about her relationship with Hamlet. Ophelia admits that Hamlet has been wooing her. They tell her to avoid Hamlet and reject his amorous advances, emphasizing the importance of protecting her chastity. Ophelia agrees to cut off contact.
That night, Hamlet accompanies the watch. The ghost appears once more. Hamlet questions the ghost, who beckons Hamlet away from the others. When they are alone, the ghost reveals that Claudius murdered him in order to steal his crown and his wife. The ghost makes Hamlet promise to take revenge on Claudius. Hamlet appears to concur excitedly. He has Horatio and the guards swear not to reveal what they have seen.
Act Two finds us some indefinite time in the future. Hamlet has been behaving in a most erratic and alarming way. Claudius summons two of Hamlet's school...