Act 6. Tragedy. Returning from the battlefield, Macbeth and Banquo, the victorious generals of King Duncan of Scotland, encounter three witches on the heath. They prophesy that Macbeth will become king, while Banquo will be the ancestor of a royal lineage. When Macbeth tells his wife about the prophecy, she unhesitatingly devises a murder plan to be executed immediately, as the king will be spending the night at their castle after the battle. She pushes the still hesitant Macbeth to commit the murder, challenging his masculinity. Macbeth kills the sleeping king, and Lady Macbeth smears his drunken attendants with blood to make them suspects in the crime. As the king's sons flee in fear for their lives, they are accused of their father's murder. Macbeth is crowned king. As a co-conspirator in the fateful prophecy, he also becomes the ancestor.