The ninja had over 400 distinctive tools and weapons to fight with and defend themselves. The most familiar was one called the "kusari-gama," a chain and sickle that could do serious damage to an opponent. But it raises questions about how they used it when fighting, and how they were able to conceal it. The ninja were also ingenious at hiding themselves. We'll do an experiment to see if those hiding techniques really worked, and we'll look at a brand-new technology for hiding people.