The first fifteen minutes of this 3-D movie finishes the cliffhangers from the third movie, EXTINCTION, with Alice's super-powered clones destroying the Japanese branch of the Umbrella Corporation. She shows up trying to kill the leader, Albert Wesker, of that section and he injects a shot that neutralizes her superpowers from the T-cells. They then crash into the side of a mountain, though both survive. After this the story goes to Alice flying a plane to Alaska. She's looking for a safe-haven called Arcadia, where the survivors from the last movie went. But when she gets there she just finds abandoned planes and their helicopter. Until she's attacked by a wild-haired woman that turns out to be Claire Redfield with memory loss. This weird spider-like device is attached to her chest. They both go in the plane back to Los Angeles and land on top of a prison where there are still survivors. Thousands of zombies are outside, trying to get in. It's there that Alice and Claire meet up with Claire's brother, Chris (Wentworth Miller of DINOTOPIA) who claims to know a way out. Only this armored vehicle is missing its engine so they have to find another way out, which happens to be an underground tunnel some zombie mutants created. They do manage to escape, just in time, and make it to a nearby ship which turns out to be named Arcadia. When they get there it seems abandoned but all the two-thousand people are in some type of stasis, to be experimented on. And yes, Wesker is there, waiting for Alice since he needs her DNA to survive.
I didn't enjoy this movie as much as RE: EXTINCTION, but it does have some cool special effects and the 3-D is amazing.