NCIS

www.youtube.com/watch

www.etonline.com/news/2010/03/
84789/index.html

ET's Kevin Frazier hops on board and visits the set of "NCIS" to help solve the mystery surrounding the death of a Marine who lived a double life. Are either of the man's two wives connected with his death?

Mark Harmon (Special Agent Jethro Gibbs) explained that both wives showed up once the Marine was found dead. "There's a lot of different issues here and a lot of different stories and different directions and, as always here, at the end it's not what you thought it was going to be at the beginning," Harmon teased with suspense.

Adding to the complication, the investigators discovered that the deceased Marine went by two different names to live out his double identity. Michael Weatherly (Special Agent Anthony DiNozzo) said, "Tony, my character, has a lot of fun extrapolating on what these wives are saying and trying to find some meaning."

Watch the video to see some behind the scenes action as they filmed the episode dubbed "Double Identity," airing tonight on CBS.