An F5 tornado can flatten a town in seconds, and this NOVA film follows the scientists trying to figure out why some storms spin up into monsters while others fizzle. Storm chasers haul radar trucks and instrument packages across Tornado Alley, racing to get equipment into the path of a developing supercell before it drops a funnel. Doppler on Wheels units scan the internal wind speeds of active tornadoes, while researchers deploy probes designed to sit directly in a twister's path and record pressure and wind data from the inside, a tactic that has destroyed more than one expensive instrument. Engineers appear too, testing how houses and building codes hold up against wind loads that can exceed 300 miles per hour. The film moves between open-road chase footage, damaged towns, and lab analysis of the data gathered, building toward the same practical question driving the whole field: whether better warning times can be squeezed out of a storm that can form and strike within minutes.