Taylor Swift, CSI

How is CSI recovering from the loss of William Petersen's Gil Grissom? By giving country star Taylor Swift her acting debut, freeing new star Laurence Fishburne to find out more about his role, and promising Petersen's return as a guest.

Grissom's last episode — for a while at least — airs Thursday at 9 pm/ET on CBS. Then the ensemble drama will turn to Fishburne's brand-new CSI, Dr. Raymond Langston, as he learns to investigate — and Fishburne learns who his character is.

"We don't know what the character is going to be," Fishburne told TVGuide.com. "The wonderful thing about this whole television thing is that we're all discovering it, we're trying to create it from episode to episode to episode."

One thing Fishburne's character won't be is a man with a genetic makeup previously considered common among serial killers. Initially, there had been talk that Dr. Langston would have such a syndrome, but the idea was later abandoned because the science that inspired it was outdated, executive producer Naren Shankar told TVGuide.com.

"Very early research on the character had indicated that there was a syndrome that was sort of more prevalent in serial killers," Shankar said. "That turned out not to be the case."

In addtion to Fishburne's new character, Swift will appear later this season as a troubled teenager whose parents own a motel. The episode will start in the present, then revisit the last year, season by season, Shankar said. The singer can expect plenty of dramatic moments, he promised. (The country ingénue also got to say a few lines on the latest Saturday Night Live, playing Little Orphan Annie.)

During a set visit, show insiders also revealed that The Exorcist helmer William Friedkin will direct the show's 200th episode — and the first in a long time to be shot in Las Vegas.

Petersen, who is still a producer on the show and is affectionately called "Billy" by his colleagues, will likely be on-set for the filming of the episode, but not in front of the camera, Shankar said.

Executive director Carol Mendelsohn promised Petersen would appear, however, in a future episode.

"Grissom will come back in an organic way, to visit or be on a case with the people that are his family," she said.

Joked Fishburne: "Billy said he would be back to make sure I didn't burn the joint down."

Asked at a news conference if he believed his casting would lead to more African-American actors landing lead roles in television dramas, Fishburne was reflective.

"That's funny because it's the question I asked Les Moonves when I agreed to take the job," he said, adding that the CBS president responded by naming The Unit star Dennis Haysbert.

Fishburne then linked Haysbert to his role on 24, in which he played the first African-American president, years before Barack Obama was a national figure.

"The good news is that I was asked to join this company because of my intelligence and because of my gifts as an actor," he continued. "And for that I am extremely grateful. The fact that I happen to be a man of color... well, I like to think of it as a bonus. In much the way that I think of the man who will become our president in a few weeks time.

"He is intelligent, capable, engaging and interested in bringing people together. And he happens to be an African-American."    

What do you think? Will the new surprises make up for the loss of Petersen?