Net gets Smart, Corbet, Britton

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. That said, here’s what seems to be shaping up:

n Britton, best known for her work on “Spin City,” is set to play Sutherland’s love interest.

n Corbet, who stars opposite Joseph Gordon-Levitt in Gregg Araki’s “Mysterious Skin,” will play the son of Britton’s character and is expected to have a strong connection to Sutherland’s character early on in the season. Casting reps Corbet’s first series-regular gig.

n Smart, who won two Emmys for guesting on “Frasier,” will play the wife of President Logan (Gregory Itzen, who’s also back).

Last season of “24″ ended with Sutherland’s character going deep underground after having faked his own death.

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