THE LONGEST DAY : Fox TV's '24'.

The ticking clock--that staple of the thriller genre--delivers more than suspense in Fox's much hyped action series "24": It also delivers the audience. After all, who really cared, when the series began in early November, that blond hunk Kiefer Sutherland had journeyed back from the realm of brat-pack has-beens to play the lead role of Jack Bauer, anxious agent in the CIA's Los Angeles counterterrorism unit? And who really cared about the show's far-fetched premise, which charged Bauer with derailing a political assassination that somehow involved the kidnapping of his teenage daughter? "24" has turned out to be a baroquely plotted but reasonably entertaining program, whose strength has been its constant unmasking of good guys who seem to be bad guys, and vice versa. But its real selling point, initially, was its format: twenty-four hour-long "real time" episodes representing the most stressful day in Bauer's life.

These gimmicky compositional parameters inspire several initial observations. The first is that the show's creators hold little stock in sleep. In its first two months, "24" has voyaged from midnight through the predawn hours without letting its principal characters take so much as a nap. Granted, political destinies are ricocheting like Ping-Pong balls on the day in question--the date of a high-stakes California primary. So handsome African American presidential candidate David Palmer (Dennis Haysbert) and his family have good reason for insomnia. As for the Bauers: Jack is charged with saving Palmer's life and exposing a traitor inside the CIA, while a frantic Teri Bauer (Leslie Hope), fretting under the yoke of a strained marriage, investigates the disappearance of their spoiled daughter, Kimberly (Elisha Cuthbert). One can only hope the entire crew will catch up on their REM cycles once rerun season starts.

The second reflection that springs to mind explains, in part, the format's appeal. The program's "real time" conceit enhances a virtual-reality experience. Viewers may not find the pace much different from that of other TV dramas: With the focus vaulting from one plot strand to another, and the inevitable commercial breaks, the show feels hectic, abbreviated, and fleeting. And the editors' favored jazzy split-screen technique, showing what two or three characters are up to at the same moment in various parts of L.A., seems a visual equivalent for the schizophrenic chronology in series that rush through days and weeks of narrative time in a single episode.

But the distance between protagonists and viewer does narrow somewhat with the idea that an hour of your time equals an hour of theirs. For evidence, one has only to check out the show's home page, which resembles a screen from a role-playing computer game. For those with the inclination and an available modem, network Web sites have, in fact, become a whole new dimension of the TV experience--eerily so in the case of www.fox.com/24. Once logged on, you can scroll not only through a minute-by-minute summary of the day's early incidents and check out credits for the soundtrack's songs, but also--surrendering to the fiction while remaining in real time--monitor Jack's incoming e-mail, read the surf report for his local beach (a customized feature of his computer's desktop, apparently), and visit the David Palmer-for-President Web site, complete with a list of bills the senator has supported (a balanced-budget amendment, for example). In an era of reality TV, infiltrating TV's reality is no big deal.

Your willingness to fritter away vast amounts of leisure time pretending you've hacked into Jack Bauer's e-mail may diminish, however, once you've faced the chilling truth the show's title underscores: If you become a fan and hang in until the final episode, you will have spent an entire day of your life watching this series. That's a day, it goes without saying, that you could have invested in learning Urdu, or doing volunteer work to aid the environment, or communing with your loved ones, or re-reading Ulysses, or immersing yourself in any number of activities more likely to be spiritually profitable. The little digital clock that pops into view periodically in "24"--usually right before a commercial--may be aimed at keeping narrative tension high; but it also serves as an unsubtle reminder that tempus fugit.

That's ironic, because the device of the ticking clock, pioneered by Alfred Hitchcock in works like Sabotage but now a cliche of thrillerdom, seems designed to exorcise our anxieties about time. When a hero defuses a nuclear bomb just seconds before it's set to explode, we can imagine for a moment that, in the battle with what Ovid called "the devourer of things," humankind has the upper hand. Even before the climax, the adventure-packed minutes of a thriller give us the illusion that life is not, as it often seems to be, slipping away as we flounder in indecision, small talk, and banality.

Compare "24" to a not dissimilar fictional work about a single day--a work that, like the Fox series, depicts alienated family members wandering through various parts of a major metropolis, separated by space and nagging distrust but destined to reunite. I am referring, of course, to James Joyce's Ulysses, that book you could have been re-reading if you hadn't been watching TV. Broken down into roughly hour-long narrative units, its streams of consciousness measuring out minutes and seconds while characters brood about the irrevocable past and the daunting future, Ulysses corresponds in numerous ways to our Kiefer Sutherland vehicle. Compare the incidents in the early sections of each:

Hour one:

"24": An assassination warning hurtles in from Kuala Lumpur. The rebellious Kimberly escapes from home. Jack shoots a colleague with a tranquilizer gun and gets access to files of a convicted heroin dealer. Meanwhile, a James Bond-style evildoer detonates a bomb on an airplane and parachutes to safety through the eddying flames.

Ulysses: Stephen Dedalus buys milk and has breakfast.

Hour two:

"24": There's a shootout in downtown L.A. The creepy parachutist buries an ID card in a homing case in the Mojave desert and snags a briefcase full of money for her efforts. Jack cuts a finger off a dead body to trace its prints. The parachutist and her lesbian lover play hardball financial negotiations with a man who has been disguised by plastic surgery. The lover gets shot.

Ulysses: Stephen Dedalus chats with his boss.

Hour three:

Jack digitally scans a thumbprint for analysis at headquarters. The Secret Service goes haywire when Palmer sneaks away for a rendezvous in which he learns his son committed murder. Fleeing from kidnappers, Kimberly gets help from a male prostitute; her friend, whom the kidnappers have drugged, is hit by a car.

Ulysses: Stephen Dedalus takes a walk on the beach and thinks.

Obviously, Joyce's novel bears the closer resemblance to the reality most of us experience, reminding us that our feet, like Stephen Dedalus's during his walk on the beach, are ever "sinking, creeping duskward over the dial floor." The creators of "24" have attempted to relieve viewers of awareness of this terrifying fact, offering a narrative so plot-packed that the audience vicariously lives each instant to the fullest. But the show is just too centered on that ticking clock; beneath the soundtrack you can still hear time's plodding chariots creaking near.