A landscape filled with mountains, the stars in the night sky or the face of a loved one... everything you see is the result of light. But for our familiar world to exist, more than 95% of the universe has to be dark - dark matter we can't see and dark energy we can barely comprehend. In this thought-provoking series, Professor Jim Al-Khalili explores the paradox that lies at the heart of physics. By manipulating light, great scientists like Galileo and Newton have uncovered virtually everything we know about the Universe. But today's search for what lies hidden in the shadows, the mind-bending quest to discover dark matter and dark energy threatens to overturn our understanding of the cosmos forever. Light and Dark is the story of everything we know and everything we don't know about the Universe.