Stunningly, 'Lost' moves forward

In a word, Yowza! Wednesday night's "Lost" season finale was a mind-blower, for sure, a radical two hours that gave us major fake-outs, an army of dead bodies, the possibility of rescue, diverse portraits of heroism, and the most touching loss of the series so far. The producers promised fans a game-changing episode, and they certainly delivered, even undermining some basic assumptions about the "Lost" format itself.

For one thing, the finale upended the whole concept of "back story" that "Lost" has popularized. The plot pieces in which Jack is a broken man (with, alas, a too-obviously fake beard), drinking and drugging himself into a stupor, turned out to be "forth story" -- flashes into the future. And in that future, at least Jack, Kate, a mysterious somebody with whom Kate lives, and another mysterious somebody who just died, appear to have been rescued from the island. Suicidal with remorse for having left, Jack takes weekly plane flights in hopes one will crash and return him to the island.

Jack's future misery casts a shadow backward: Knowing that rescue won't be a happy thing darkens our perception of Jack's struggles to get everyone off the island. It reverses the tone of the show. Will we continue to root for escape from the island next season, or will we reconsider Locke's belief that they need to stay put?

That grim forth story, which saw Jack referring to his father as if he were still alive, also sets the previous three years of "Lost" into question. Have there been other "Lost" forth stories that we assumed were back stories, such as when Hurley and Libby were seen together in a mental institution? Yes, a game-changer indeed.

The emotional peak of the episode, which relied more on emotional twists than action scenes, was the death of Charlie. Like other characters on "Lost," Charlie had reached a state of well-being before he died, alone in a room in the Looking Glass underwater station that filled with water in excruciating slo-mo. He was brave enough to write "NOT PENNY'S BOAT" on his hand for Desmond before the water consumed him, but unable to communicate, also, that he had just had a brief conversation with Desmond's beloved.

Far less wrenching were the many, many deaths of the Others, who finally fell at the hands of the good guys. The first ambush saw Others fall, and the Underwater Others also fared poorly. And Hurley did his part, zooming the "Shambala" van into the camp to save Jin, Bernard, and Sayid and knock off a few more. Ultimately, Tom seemed gone for good, too (not Mikhail, so naked without his eye patch; wasn't that him with the grenade outside Charlie's window?). And Ben was alive, but in the custody of the crash survivors, bloody and powerless.

By the end of the finale, I was back in love with "Lost" in a big way. No other show has the same power to put the viewer in such a profound, almost philosophical state of wondering. We tend to feel what the crash survivors feel -- out to sea, unable to figure out what's happening, but vitally interested in learning the truth. The season began poorly last fall, but in the past few weeks, "Lost" has been on a great roll. The show won't return until February, for a 16-episode season, and it's a testament to the writers and producers that I'm quite willing to wait that long for a few more answers.

Matthew Gilbert can be reached at gilbert@globe.com.