Horatio Caine (David Caruso) requests that Las Vegas CSI Ray Langston (Laurence Fishburne) come to Miami when a severed leg found in the Everglades is traced back to a girl who went missing in Las Vegas a week earlier.

Tonight's episode of "CSI: Miami" is the first of a three-part story that takes Langston from Miami to New York and back to Las Vegas.

"[It is about] human trafficking … girls who are forced into prostitution," Fishburne tells ET. "Their organs are harvested. They have to become surrogate moms. They get transported across the country on the interstate."

Fishburne tells ET that the idea for a crossover began when he first got the job on "CSI: Crime Scene Investigation." "We ran into each other at a big party. I had just signed on for 'CSI' and David said, 'How about a crossover?' I was, 'Hey, I just got this job.' It has been in people's minds for a while," he says.

The two men also tell ET that they are long-time friends, who got a chance to work together back in 1990 on the film, 'King of New York.' Then Fishburne jokes that Caruso stole his signature sunglasses bit from him and demonstrates his impression of Caruso as Caine. Watch the video to see if he has it down!

The "CSI" trilogy begins on "CSI: Miami" on Monday, Nov. 9 at 10 p.m., moves to "CSI: NY" Wednesday, Nov. 11 at 10 p.m., and wraps up on "CSI: Crime Scene Investigation" Thursday, Nov. 12 at 9 p.m., all on CBS.