give me an example of foreshadowing

In a mystery novel, the main character finds a mysterious letter that hints at a dark secret from the past. Later in the story, it is revealed that the letter was a key piece of evidence in solving a crime that had been committed years ago. This letter served as foreshadowing for the bigger plot twist that was to come.

SHORTEN THIS PLEASE

In a mystery novel, a mysterious letter foreshadows a dark secret from the past that becomes key to solving a crime.