Has there ever been a show that jumped sharks so often and so adroitly as Lost? Shark-jumping is usually the beginning of the end for a show, the overblown moment when we realize that its best days are behind it. Lost began on a high note — the plane crash — and has spent the last two years trying to convince people that it isn’t all downhill from there. With all the characters, mysteries, and mythologies that Lost’s producers keep adding to the show’s overflowing heap, I’m constantly shocked to find that it hasn’t collapsed under its own weight.

Lost’s increasingly baroque plot is propped up by its characters. Some of them are more intriguing (Mr. Eko), more sympathetic (Sun), or better fleshed out (Locke) than others (Claire), but as a group, their personalities and backstories provide an important contrast to all the hatches and buttons and magnets and whatnot. Whenever the flashbacks seem to drag, or fail to add any useful information, I just remind myself of what happened to Alias when it abandoned Sydney’s boring alternate life: we learned that a steady diet of mysteries, cliffhangers, and plot twists can become kind of numbing without something to balance it out. (I’m looking at you, The X-Files.)

The mysteries are still what keep people coming, of course, and they continue to get more densely knotted. Much of the fun in Lost is to be found offscreen: on message boards and fan sites, where people attempt to decode the meanings of the show’s various hints and red herrings; in podcasts like the one featuring Lost’s executive producers, who drop a few extra hints of their own while dorking out; and in ancillary media like fake Hanso web sites and ghostwritten novels. These oblique hints and competing theories are not so much about clearing things up as they are about muddying the waters even more than they were before — and about keeping Lost in viewers’ minds over the long summer hiatus.

What people are now calling “linear programming” is still at the center of it all, though, and Lost stands or falls on the quality of the actual TV show itself. Luckily, the quality remains excellent: good writing, good acting, and excellent production keep Lost running at a high level. Pundits who enjoy predicting the demise of traditional television might point to all the extra content that surrounds Lost as a sign of the future, but Lost is actually a sign of why linear television still matters, and will for a long, long time: It’s a television show that doesn’t ignore new media, or work against it, but sits at the center of an entire constellation of media artifacts. It takes something pretty compelling to inspire all this activity (the failure of any new shows to gain any traction with audiences is strong evidence of this), and it’s not clear that mobisodes will be able to generate this kind of energy any time soon.

So yeah, Lost is a pretty important show. But here’s the real question: What the hell is up with that foot?