Read the following excerpt from a fictional narrative:
"As the leaves turned crisp and golden, Ella felt an unease she could not shake. Each morning she awoke with the sensation of shadows creeping into her dreams, whispering secrets she dared not voice. The air grew heavy, pregnant with an unspoken tension, yet the world outside continued its cheerful facade. The town bustled with laughter and the vibrant colors of autumn, but all Ella could sense was the impending chill of winter lurking just beyond the horizon."
Based on the excerpt, what can be inferred about Ella's emotional state and the underlying themes of the narrative?