Thy letters have transported me beyond
This ignorant present, and I feel now
The future in the instant.
– William Shakespeare
Macbeth, Act 1, Scene 5. You can see why Lady Macbeth is often regarded as the Fourth Witch. She now believes that she can prophecy the future like the Witches. The future is already here as far as she is concerned, the future being a world where Macbeth takes his place on the throne.