Smoke Gets in Your CSI's

While Calleigh and Ryan investigate a body inside the attic of an empty house, someone traps them in there and sets fire to the house. Later, Calleigh suffers from respiratory problems, prompting Eric to admit to Calleigh that "he can't imagine living his life without her." Alexx Woods comes back to save Calleigh from dying. Meanwhile, the rest of the team keeps searching for the murderer of that man found at the house. They discover a black market for human organs.