When an undersea treasure hunter is found spear-gunned to his boat, the CSIs find themselves dropped into the murky depths of modern day piracy.

The team is called to a crime scene only to find that their 'body' is still alive, and the trail of evidence stops dead on a man already behind bars.

The CSIs must race against the clock, the disappearance of a teenage girl poses a question that can only be answered by a 12-foot endangered reptile.