Crop circles start showing up in written records as early as the 1600s, but the phenomenon does not become a worldwide sensation until the 1970s, when elaborate patterns began appearing in English wheat fields in large numbers. This episode of UFO Files lays out the two camps that have argued about them ever since: researchers who point to unexplained heating and cellular changes in the flattened stalks as evidence of some unidentified energy source, and skeptics who note that a simple circle can be stamped out with boards and rope in under an hour, while the more elaborate geometric formations take teams of hoaxers all night. Interviews on both sides walk through the mathematical precision of the designs, some invoking ideas about higher intelligence or altered consciousness, others treating the same precision as proof of careful human planning. England's fields anchor the visual evidence throughout, shown from the ground and from above, as the episode weighs competing explanations without settling on one.