In Act 1 Scene 7, Macbeth begins to have doubts about killing Duncan. This is because of how Duncan has placed so much in trust him and is his fellow kinsman. Before this doubt can spread any further Lady Macbeth enters and begins questioning his manhood for he introduced the idea in the first place and not following up would make him a coward. This convinces Macbeth to go forth with the act. The questioning of Macbeth's manhood by Lady Macbeth and her constant antagonizing of Macbeth shows that she is the true villain in this play and Macbeth is but a brainwashed victim.