What evidence is there of foreshadowing?

Foreshadowing is when the author leaves a detail for the reader as a clue giving them an idea about what will happen later in the story. Foreshadowing can come in many forms, and can be obvious, or very difficult to understand. The best foreshadowing is integrated into the story seamlessly, so only the most clever notice before the event is revealed. A real life example would be that a change in air pressure is often a foreshadowing of rain.