What this means structurally is that 24 is almost totally a plot-based show. The creators aren't just using the ticking clock technique to speed the story as it nears the end. They have to fill real time, and real time is boring. That means they have to rely heavily on cross-cut storytelling in which we cut between a number of story lines happening simultaneously.

Cross-cut storytelling allows you a number of plot advantages. First, you increase suspense by showing two lines racing to the same point. For example, will the hero save the girl tied to the railroad tracks before the train runs her over?

Second, the cross-cut allows you to remove any action that is boring. Instead of watching someone drive somewhere or even have a conversation (heaven forbid), we can jump from crisis point to crisis point, so long as we have enough story lines going at once.

But notice that puts tremendous pressure on the writers. They have to not only create a number of story lines that are believably happening at one time, they have to weave them together so that each helps build the other and both the episode and the season have a dramatic line.

That's really hard. One of the pleasures for me watching the show was seeing how the writers accomplished these feats of plot with such success. Plotting is the most under-estimated of the major storytelling skills, so watching these writers perform their high wire act over 24 hours of tv time was pretty amazing.

But as they say in basketball, you live by the sword, you die by the sword. When your show is built almost entirely on plot, you lack the character definition to make some of your plot tricks believable. And when that happens, the plot mechanics immediately become obvious and audience scorn is severe.

To the writers' credit, this didn't happen often. However, I laughed out loud when they used the old amnesia trick for Jack's wife.

The most grievous example of the false plot trick occurred on the biggest plot twist of the season. In the second to last episode, the writers revealed the identity of the hero's opponent-ally. Because there had been virtually no character work during the series, and because there had been no clues woven in earlier, this reveal not only felt false, it seemed like a betrayal of the audience.

Revealing the hidden opponent is a common problem, not just with plot-based stories but, more specifically, with detective stories. Detective writers are so worried that the audience will guess the big reveal of the killer early, they often give no clues at all. But as the master, Agatha Christie, once said, that's cheating. The audience should be totally surprised, but also be able to think back through the story and realize the information was there all along.

Ironically, what saved the writers of 24 is the fact that their big reveal happened at the end of the second to last show. By that point, the only people who were watching were real fans who had already forgiven lesser plot grievances.

What will be interesting to see is how the writers of this show overcome another weakness inherent to plot-based shows, the second season blues. When you put all your eggs in the plot basket of the first season, the audience feels they have had the experience. For example, when Laura Palmer's killer was revealed at the end of Twin Peaks' first season, no one felt they needed to come back the next year.

Now that I've seen Jack Bauer's worst nightmare, I don't think I want to see a different one that's almost as bad.