"Arianwen and the Key to Light" follows a young girl's journey through magical realms where she learns about the science of light. Armed with an enchanted key and guided by Lugh, a glowing figure made of light, Arianwen explores the wonders of sunlight, color, shadows, refraction, and more. As she travels through fantastical worlds, Arianwen uncovers how light shapes the natural world, powers technologies, and creates beauty. This adventure inspires children to discover the magic of light and how it influences everything around them, making science fun, exciting, and full of wonder.