Walter and Calleigh are at a Miami home investigating a grizzly double murder when a tornado strikes the house and sends them both diving for cover. Walter emerges from the wreckage to find the crime scene destroyed and Calleigh missing. In the aftermath, the CSIs uncover a bruised but not broken Calleigh nearby, trapped under debris. With evidence lost to the storm our CSIs follow the path of destruction to a second body in a building nearby, which appears to be unrelated to the original murder. Our CSIs set out to prove otherwise, believing this is no coincidence. As the new evidence and body count grows, they encounter a team of tornado chasers, an edgy soldier-in-training, and a too good to be true rescue volunteer who are all viable suspects.