Lost is that rarity: A smash hit that deserves to be. Rich with character interaction, unrelenting suspense and moments of startling revelation, it demands attention from its stunning first 15 minutes and, if anything, gets more and more compelling as it bumps along. Better yet, it rewards obsessive viewing by planting a wealth of small details that don't pay off until many episodes later: Among them, just what's going on with Locke, the one castaway who actually seems cheery in the aftermath of the disaster.

The first season comes off as an organic whole, with all the deepening and proliferating mysteries of the island hinting at a some kind of involved, uncanny but very specific explanation. Everything feels planned. The one genuine danger evaded so far, unfortunately a real one given the input of Alias creator J.J. Abrams, is that the plan might ultimately amount to making things up on the fly. If the creators don't know where they're going with this thing, expect building viewer frustration by season three.

DVD extras include a visit to the set by talk show maven Jimmy Kimmel (who ultimately encounters the show's unseen monster close up) and "Tales from the Island" that include a featurette on the creation of the backstory's fictional rock band Driveshaft. "The Art of Matthew Fox" features black-and-white production photographs by the actor. "The Genesis of Lost" details how a nebulous concept about castaways morphed into the science-fiction show it is today. Several episodes have extensive commentaries. The commentary for episode four, "Walkabout," with its stunning revelation about castaway John Locke, establishes that the forces behind the scenes wanted to give the episode the hilariously apt title "Lord of the Files."

Most fascinating are the audition tapes of the various regulars, dating back to an early script in which the doctor, Jack, died in the first episode. In that draft, Kate speaks lines in which she starts to assume leadership of the castaways. Aside from this tantalizing glimpse of a storyline abandoned, we are also treated to actors reading for parts other than those they were eventually awarded. Yunjin Kim, who plays Sun, acquits herself well reading for Kate. Meanwhile, Matthew Fox, who became Jack, is shown reading for both that role and for the role of sleazebag con man Sawyer. (He's downright psychotic as Sawyer.) Rotund Jorge Garcia, who became everybody's favorite as the star-crossed Hurley, also reads for Sawyer, not quite managing that role's dangerous intensity. One suspects that if he'd gotten the part, it wouldn't have featured quite as many shirtless scenes. The best audition? Young Malcolm David Kelley, who shows real wonder during Locke's monologue on Backgammon.