Everything’s quicker these days. Even “24.”

The Fox network said on Monday that it was bringing back “24,” the counterterrorism drama that stoked the American public’s fears after the Sept. 11 attacks, as a 12-episode series next year. The show’s original conceit, a story that plays out in real time over a 24-hour period, will stay intact, but the producers will skip some hours and condense others to fit into the 12-hour format.

Kiefer Sutherland will return in the title role of Jack Bauer, a secret agent who will stop at nothing to stave off impending attacks.

“It’ll be dictated by the plot,” Kevin Reilly, the chairman of Fox Broadcasting, told reporters at a conference call on Monday. He suggested that the time constraints would be liberating for the producers, who have a long time to work on the story: it is not expected to have its premiere until May 2014.

The new version of “24,” with the subtitle “Live Another Day,” will be shown for 12 weeks in a row as part of what Fox calls a “limited series” strategy. That means that it is intended to be a one-time event — though in television, those plans can always change. Mr. Reilly acknowledged that there could be more installments in the future.