Life on the Oahu set of Lost isn't always a day at the beach. On this sweltering March afternoon, for example, ABC's cult hit about castaways on a time-warped tropical isle has chosen to shoot in...a rock quarry. Amount of fun currently being had: Zero. The horses are jumpy from machine-gun fire. Executive producer Jack Bender is directing with an ice pack to his face after walking into a crane. And Michael Emerson a.k.a. Benjamin Linus, the show's villainous über-Other is broiled, thanks to his curious wardrobe requirement: a woolly winter parka.
''Definitely a no-glamour zone,'' says Emerson during a brief respite from shooting Lost's first episode since the writers' strike interrupted production last November. ''I thought we would ease into things. Instead, I get this all-Ben extravaganza: combat, riding horses, foreign languages. And piano playing! All waaaay outside my comfort zone. How can you work two weeks and feel like you need a vacation already?''
Some sympathy for Lost's biggest devil? Not a polar bear's chance in Tunisia. Besides, there's crucial work to be done. You'll start seeing it on April 24, when Lost returns with the first of five fresh episodes that will wrap up its buzzy, strike-abbreviated fourth season. EW spent three days on the set of the drama, and judging from the looks of things like the corpse that washes up on the sandy shores of Camp Jack and the raging gunfight that will decimate Camp Locke the first episode back, ominously titled ''The Shape of Things to Come,'' will launch the endgame with downright apocalyptic thunder. The ensuing four installments will answer some of the season's biggest questions: How did the much-vaunted Oceanic 6 leave the Island? What happened to those left behind? Why is Sayid (Naveen Andrews) killing people for Ben in the future? And who's rotting inside that darn coffin? ''It's big and epic,'' promises Matthew Fox (Jack). ''Our first eight episodes, by design, were all set up for these episodes to come. That we're doing just five instead of eight means they're even more packed with plot. It's payoff time.'' More momentously, the finale whose Big Twist is code-named ''Frozen Donkey Wheel'' will set the stage for another series reinvention. Citing the seventh Harry Potter book, in which J.K. Rowling broke her usual year-at-Hogwarts template, executive producer Damon Lindelof says, ''We're taking the same approach. You think the show is, 'Okay, they're on the Island, and then whoosh you're in the past or the future.' By the end of season 4, I think the audience is going to go, 'How can the show continue to be that?' And they are absolutely right.''
NEXT PAGE: ''I think everybody here feels that we are now a more mature show, that we are now a show for grown-ups, because we're going to see that like in life, there may not be happy endings for many of us on this Island.''