When a massive storm cell threatens to strike South Dakota, the storm chasing teams travel the state's highways in hopes of witnessing powerful tornadoes, and their wish is granted when the storm spawns a series of twisters. Sean is devastated when Dr. Wurman recommends that TIV2 be sent home. Meanwhile, all three teams of storm chasers surround the slow moving EF4 Bowdle tornado as it demolishes farms and transmission towers.