Every two years, teams of castellers converge on Tarragona, Spain, to see who can raise the tallest, most complex human tower without it collapsing. The film follows the training and rivalry behind this Catalan tradition, where children climb to the top of stacks of bodies while grown men and women form the base and supporting columns beneath them. Interviews with team members explain the discipline involved, the injuries that come with the sport, and why entire towns organize their calendars around practice nights and competition days. Cameras get in close during the builds themselves, catching the moments a tower wavers, the crowd's reaction, and the relief or disappointment when it finally comes down, intact or not. The film treats the castells as both athletic feat and civic ritual, a demonstration of trust between strangers stacked five and six people high, and lets the competition in Tarragona serve as the structure for understanding why Catalans keep building them.