The CBS drama "NCIS" (Tuesday night at 8) joined a select group of prime-time TV shows recently when it aired its 200th episode. Only 62 series -- out of the thousands that have filled network and cable channels -- have reached the milestone.
And "NCIS" shows no sign of slowing down. It's consistently the highest-rated drama in the weekly ratings and has 13.7 million Facebook fans. The popularity is global: It airs in more than 200 international markets and is heard in 20 languages.
The show appeals to more than just older viewers. It has higher ratings with viewers ages 18-49 -- a demographic advertisers love -- than "Glee," "Dancing With the Stars" and "The Office." So how does a series about the weekly exploits of a team of Navy investigators become such a hit? Series star Mark Harmon says it started with mediocrity.
UNDER THE RADAR "I think, from the very beginning, we were a show that wasn't good enough to get all that noticed and wasn't bad enough to get canceled," Harmon says.
That might sound strange, but he has a point. TV shows that start as big hits have a tendency to fade quickly, such as "Twin Peaks" and "Glee." Series that start slowly rarely last past a few episodes, such as "The Playboy Club." Because "NCIS" started out in the middle of the viewing numbers, the series had time to build a solid foundation of story lines and characters.
CHARACTERS COUNT "NCIS" is loaded with characters, from the gruff boss played by Harmon to the quirky lab rat brought to life by Pauley Perrette. Toss in a nerd (Sean Murray), a swaggering hero (Michael Weatherly), a suave British doctor (David McCallum) and a hot foreign agent (Cote de Pablo), and the show has a host of interesting places to go.
Executive producer Gary Glasberg credits series creator Don Bellisario for establishing such a versatile character blueprint.
"There was a foundation that he started with, a brilliant foundation of story and character that was there. And over the years, we just sort of kept scratching the surface of it. And to be nine years into a show now and still have so much to work with is a real comment on what Don came up with to begin with," Glasberg says.