This is the season finale of 'CSI: Miami' (Mon., 10PM ET on CBS). And things are getting tense.

[Spoiler alert.]

The CSI team, led by Horatio Caine (David Caruso) is on the trail of a serial killer (yet again). But this time, the killer may be coming to them. The bad guy manages to attack the good guys where they live, using the weapon of chemical warfare. First, Caine gets a letter from the villain with this cryptic message: "They All Fall Down."

This turns out to be the case. The agents in the lab receive more letters from the killer, and then, one by one, they begin to pass out and fall to the floor. As the chemicals take effect, the CSI team is knocked unconscious. Will they survive?