BURBANK, Calif.

WHAT ever happened to the four-toed statue? Why do some inhabitants of the island never seem to age? What is the Smoke Monster? And, as one of the time-traveling survivors of the crash of Oceanic Airlines Flight 815 asks in the premiere of the new season of “Lost,” Wednesday on ABC, “When are we now?”

With 34 episodes to go in its two final seasons, the stories of nearly 100 characters to wrap up, several Dharma stations to keep track of and a whole lot of time traveling going on, the writers of “Lost” are doing anything but winding down. Yet their task  untangling the seemingly impenetrable mass of plotlines that have become addictive to some viewers of the show and alienating to others  is relatively simple compared with that of Gregg Nations.

A co-producer and the show’s longtime script coordinator, Mr. Nations has become the keeper of what has been found on “Lost,” charged with tracking everything that has happened and will happen to the characters on and off the island, in addition to charting the many mysterious characteristics of the island itself.

While most television series maintain a so-called bible  a guide to characters and plotlines that are developed by the creators but revealed over multiple seasons  few if any shows have twists and turns as byzantine as those on “Lost.”