Some people got impatient with Lost. Frustrated by the plot's mounting questions, and the lack of answers to existing questions, some viewers left the show stranded on its own island, and while it remained popular, it lost some of its zeitgeist-defining aura. I have always loved the show, but even I'll admit that seasons two and three weren't quite on the same level as the first. So please take me at my word when I say that if you were one of those frustrated fans, you need to come back into the fold. Right now, Lost is the best it's ever been.
With last season's game-changing finale "Through the Looking Glass," in which it was revealed that Jack's (Matthew Fox) pill-popping, booze-swilling flashback was actually a flashforward, with both him and Kate (Evangeline Lilly) off the island, Lost executive producers Carlton Cuse and Damon Lindelof began prepping for the sprint to the finish line. After the third season, they secured a deal with ABC for a definitive series endpoint (season six in 2010), with each remaining season to have fewer episodes than usual so that they could be broadcast with no annoying hiatuses.
Judging by season four, it looks like that's all the show needed to get back at the top of its game. There's no more stretching the story to ridiculous lengths, no more pointless filler episodes. Cuse and Lindelof know when the show's ending, and they're loving it.
At the beginning of the season, the survivors of Oceanic Flight 815 are split down the middle, into two camps: those like Jack who trust that the people on the mysterious freighter are actually going to rescue them, and those like Locke (Terry O'Quinn) who distrust the intentions of the so-called rescuers after Charlie's (Dominic Monaghan) cryptic message, "Not Penny's boat." Locke takes Hurley (Jorge Garcia), Claire (Emilie de Ravin), Rousseau (Mira Furlan), Ben (Michael Emerson), Karl (Blake Bashoff), and Alex (Tania Raymonde) with him to the Others' barracks, the safest place on the island. Oh, Sawyer (Josh Holloway) also agrees to go with Locke, much to everyone's surprise; this puts yet another spin on the Jake-Kate-Sawyer love triangle and casts real doubt on the freighter's purpose.
Caught in the middle of these two factions is the freighter's science team, which is sent to the island for reasons no one seems quite sure of. Unlike last season's unsuccessful attempt to shoehorn Nikki and Paulo into the main cast, each member of the science team is a unique, valuable addition. There's anthropologist Charlotte Lewis (Rebecca Mader), ghost whisperer Miles Straume (Ken Leung), pilot Frank Lapidus (Jeff Fahey), and the best addition of them all, physicist Daniel Faraday (Jeremy Davies). The sterling episode "Confirmed Dead" gives us a taste of their backstories, and though the 2007 Writers Guild of America strike meant that two episodes had to be cut from the season, including one which expanded upon the team, Cuse and Lindelof have promised we'll be finding more about them soon enough.