As producers Damon Lindelof and Carlton Cuse state in their commentary on the fifth-season premiere, "We're doing time travel this year," and the pile-up of flashbacks and flash-forwards will make even the most dedicated fan dizzy. Ben, Jack, Hurley Jorge Garcia, Sayid Naveen Andrews, Sun Yunjin Kim, and Kate Evangeline Lilly arrive to find that Sawyer Josh Holloway and Juliet Elizabeth Mitchell have been part of the Dharma Initiative for three years. The writers also clarify the roles that Richard Nestor Carbonell and Daniel Jeremy Davies play in the island's master plan, setting the stage for the prophecies of Daniel's mother, Eloise Hawking Fionnula Flanagan, to play a bigger part in the sixth and final season.

Dozens of other players flit in and out, some never to return. A few, such as Jin Daniel Dae Kim, live again in the past. Lost could've wrapped things up in five years, as The Wire did, but the show continues to excite and surprise. As Lindelof and Cuse admit in the commentary, there's a "fine line between confusion and mystery," adding, "it makes more sense if you're drunk." Other extras include deleted scenes, featurettes, a "lost" episode of Mysteries of the Universe, and commentary from writers Edward Kitsis and Adam Horowitz on "He's Our You," a reference to Sayid, who tries to change the future by changing the past. --Kathleen C. Fennessy