CBS' Thursday-night powerhouse "CSI: Crime Scene Investigation" nearly lost cast members George Eads and Jorja Fox in a recent contract spat with network honcho Les Moonves. In the end, all was resolved, but now it looks like the forensic drama's successful Monday-night spin-off, "CSI: Miami," is going to suffer a loss of a more permanent kind, when it returns for its third-season premiere on Sept. 20.

"In the first episode," says executive producer Ann Donahue, "we're actually losing a beloved CSI. Can't tell you which one, but a CSI is going to die in the line of duty."

It's certain that the fatality won't be Horatio Caine (David Caruso), the steely-eyed head of the South Florida homicide and forensic-science unit. That leaves investigators Tim Speedle (Rory Cochrane), Calleigh Duquesne (Emily Procter) and Eric Delko (Adam Rodriguez).

While cast and producers are keeping mum on who goes down (although rumors point to Cochrane), that person will be the second to leave the show, following Kim Delaney, who departed her role as CSI Megan Donner during the first season.

As for a replacement, Donahue says, "We are looking at men and women, no firm decision yet."

Asked if the casting might drive the character, Donahue says, "That's exactly it. You can create a character, and then you can see an actor that doesn't fit that at all and go, 'That's interesting. Let's go with that instead.'"

Along with tragedy, Donahue promises other big thrills for the opener.

"Our crew's down there [in Miami] filming," she says, "and we're doing some great things. We're crashing a bridge. We have a couple; they're on a causeway. Something hits the bridge, the bridge breaks, and they fall into the water. We just like to show the unexpected. Grab people, show them their greatest fears and then solve the crime. And the boat that caused the bridge failure, there's a body on it.

"Also, there's an area in the Everglades where the bay meets the 'glades, where it's alligators and sharks. A kidnapped boy is left out there to die. We do see a shark kill a man. There's a drive-by Miami-style, which is guys on cigarette boats. It's an homage [to 'Miami Vice']."

While Caine survives the opening episode, that doesn't mean he has no worries. At present, Caine has let his wayward brother's widow, Detective Yelina Salas (Sofia Milos), think he is the father of a child that actually belongs to her late husband. At the same time, Yelina is dating Internal Affairs office Rick Stetler (David Lee Smith).

"Horatio let Yelina go," Donahue says, "and he's watching her have a relationship with a man ... I'm not going to say he's a scumball, but he's a man who's already opened a file on Horatio.

"He's looking, and if you look, if you put anyone under a microscope, the best person -- even a good cop -- there are going to be times they don't look good. They do things that are suspect, because a good cop will go a long way in furtherance of the victim. So the season's going to have a pretty big ending. All I can say is, episode 24."