Seven and a half months later, we're still picking brain matter off the wall. There we were, innocently watching Lost's season 3 finale on May 23, trying to figure out the direction of the flashback sequence in which Dr. Jack Shephard (Matthew Fox) had become an oxycodone addict/Grizzly Adams look-alike, when suddenly...WTF?! This is a flash-forward?! He and Kate (Evangeline Lilly) are both off the island?! Wait...now he wants to go back? This stunning episode in which Jack led the castaways to near rescue (or not, depending on those freighter folks), and Dominic Monaghan's Charlie embraced his watery fate represented a return to glory for ABC's acclaimed island drama, which had left critics and fans disgruntled earlier in the season. It also marked another potent acting performance by Fox, 41, who's served as a Lost leader, on screen and off, ever since Flight 815 crashed in 2004. ''I felt, and heard many other cast members say, that the show had hit a new plateau and that Matthew in particular had gone there with it,'' says Michael Emerson, who plays Jack's eerie nemesis, Ben.
During a strike-created break from shooting season 4 eight episodes were completed before the shutdown we caught up with Fox (who also stars in next month's political thriller Vantage Point) near his Manhattan Beach, Calif., home. He looked back at the finale as well as the producers' decision to end Lost for good after 48 more episodes, and even offered us a peek into the future before the series returns on Jan. 31 (now on Thursdays at 9 p.m. set those DVRs!). ''I think the show's going to be better in its last three seasons than it was in the first three,'' he notes, adding, ''There's going to be some huge mind-blowing s---.'' You heard the man: Helmets on. (And for more clues about how Lost will play out from here, don't miss EW.com's video interview with Matthew Fox, including behind-the-scenes footage from his on-the-beach photo shoot for Entertainment Weekly.)
ENTERTAINMENT WEEKLY: What was your first reaction to the big twist in the season finale?
MATTHEW FOX: Something like ''Holy s---!'' It really caught me off guard. I'm not sure I ever thought that people were going to get off the island.... Damon [Lindelof, who co-wrote the finale with fellow exec producer Carlton Cuse] did such an amazing job of orchestrating something that when you're looking at it for the first time it feels like a flashback, but there'd be little things that are a little odd like why Jack seems so ridiculously messed up. You think it's in relationship to his marriage falling apart, and then boom, you go, ''Oh, my God, this is a leap forward in time. What does that mean? Why is he suicidal?'' I just think that's great.
How hard was it to keep the big twist a secret?
I was walking around with the cat-that-ate-the-canary look on my face. And when I would get questioned on it, I would say, ''I can't say anything, but, man, I can't wait for you to find out.'' Even a lot of the crew didn't know. When the scripts went out, the last scene of the episode was missing. So when we started shooting, the crew was just like, ''Oh my God!''
Did you guys shoot any decoy endings?
We didn't, for that. But that has been done, which I just recently discovered.
Do you mean for last season or this one?
This one coming up. I wasn't part of that particular scene. I thought I knew what was going on in the scene, and then found out that I didn't.
NEXT PAGE: ''A truck might pull up and a bunch of dudes in suits get out and mow us down with Uzis. [Laughs] Seriously.''