Humans prefer moderation - neither too hot nor too cold, neither too light nor too dark. But Earth doesn't cater to our preferences. Our planet offers an abundance of extreme conditions, and people everywhere have had to learn to adapt to their surroundings. "EXTREME! - Light and Dark" is a journey to the brightest and darkest inhabited areas of the world: places where a cloud hardly ever crosses the sky - or months pass without a single ray of sunlight reaching the ground. How does so much light, or so little, affect the mindset and emotional well-being of the people who live with it? How do they protect themselves? And how do they take advan- tage of their situation? Following the previous episodes of "EXTREME!"-"Valley Deep - Mountain High", "Drought to Deluge" and "Freezer to Furnace"- this episode brings to life the brightest and darkest places on Earth in spectacular images.