Imagine waking up one day and realizing that everything you thought you knew about the world – literally the world – might not be true. The Earth, that trusty old spinning marble we call home, isn't a sphere at all. No, according to some, it is flat as a pancake (or a pizza, if we're being generous). Planes are flying in carefully orchestrated circles, horizons are playing optical tricks on our eyes, and astronauts are really just actors with good CGI. Sounds like the plot of a new sci-fi blockbuster, right? Yet for thousands of people, this is reality – or at least their version of it. The Flat Earth phenomenon isn't new. It has ancient roots, woven into the cosmologies of civilizations long past. But what's fascinating is how, in a time when we can send rovers to Mars, carry pocket supercomputers, and live-stream cat videos from space stations, this belief has not only persisted but thrived. Why? That's the question that inspired this book.