Stars, hide your fires;
Let not light see my black and deep desires:
The eye wink at the hand; yet let that be,
Which the eye fears, when it is done, to see.

– William Shakespeare

Macbeth, Act 1, Scene 4. Just after King Duncan names his son Malcolm his successor, Macbeth asks the stars to hide their light so that his disloyal desire to take the throne cannot be seen by anyone. He means to achieve this goal by killing Duncan if necessary. A metaphor is used to describe his evil desires as “black and deep.” In this passage the stars are also personified. Macbeth speaks these lines in an aside, because he wishes to conceal his ambitious intentions from other people. Among the themes in play here is appearance vs reality, also fate and free will. Macbeth is not prepared to leave it to fate for the Witches’ prophecy of him becoming king to come true. He decides to act on his own free will and commit regicide to ensure his ascent to power.