Macbeth is a tragedy written by William Shakespeare, believed to be first presented in 1606. After ordering his men to murder his good friend Banquo, Macbeth sees the ghost of his friend, during a dinner with some nobles. Being confronted by his murdered victim, Macbeth loses self-control and completely ignoring his important guests, he interacts and discusses with the ghost. His distress and despair are signs that he lost control and he surrenders to his extreme guilt. Shakespeare wants to show that our evil acts will eventually come back to haunt us.
It basically means to spoil carefully laid plans, For example;
"Don't upset the apple cart by revealing where we're going."
