According to Variety, Fox is keeping a tight lid on the plot and cast for the upcoming fifth season of hit drama "24," but some details are starting to leak out.

Thesps Jean Smart (Garden State), Brady Corbet (Mysterious Skin) and Connie Britton (Friday Night Lights) will appear as regulars next season, according to those familiar with casting for the skein.

Also, Fox again plans to launch "24" as a four-hour, two-night event in January.

On Thursday, Fox Entertainment prexy Peter Liguori declared Fox's intention for a "complete lockdown" on information about the upcoming season of the show.

"It's going to take some bamboo shoots for me to talk about '24,' " he told reporters.

Indeed, both the network and 20th Century Fox TV/Imagine declined to confirm or deny the new additions to the show. Exec producer Evan Katz also was tight-lipped at Fox's summer TV Critics Assn. press tour bash Friday in Santa Monica.

However, it's believed Kiefer Sutherland (Jack Bauer) will be back, and producers have all but confirmed Mary Lynn Rajskub will return as Chloe. A couple of other regulars from last season may be back as well, but it seems the bulk of the season-five cast will be made up of newcomers.

Getting a precise handle on the new roles is difficult because of the secrecy surrounding the new season.