In act II, scene II, the queen says to the king: "I doubt it is no other but the main, / His father's death and our o'erhasty marriage." Hamlet's mad state of mind is attributed to his father's death. In spite of the queen's ignorance of Hamlet having seen his father's ghost, she is able to sense the distress in her son. The queen tries several things to make Hamlet forget and mourn his father properly, such as seeing old friendships. The queen might also feel guilty for the marriage with the old king's brother, which could be considered adultery according to biblical principles.