The townsfolk of “Jericho” (7 p.m., CBS) have survived a nuclear blast, and the show has endured a season bisected by a two-month hiatus that may have caused erosion in interest and audience. Will “Jericho” survive to see a second season? That decision has yet to be officially announced.

For all of the atomic fallout and post-apocalyptic gloom, the biggest threat to “Jericho” has been the looming shadow of “American Idol.”

On tonight’s season’s finale, a member of the town government does not survive a shootout with outsiders.

¢ “Lost” (9 p.m., ABC) also saw its season interrupted by prolonged intermission. But this series has rebounded creatively and has recently offered viewers a series of tantalizing puzzles and explanations about the meaning of it all.

I’ve long since concluded that the mysteries of “Lost” will never be fully explained and that we will always have more questions than answers.

Last week’s most enigmatic moment occurred just as Locke had locked Sawyer in a cell with Locke’s evil father. Sawyer is screaming bloody murder. Did I mention the cell was in the belly of an old slave ship? And who should come along but the mystery French woman Rousseau. What’s she doing there? Just picking up some dynamite. “Watch out!” Locke warns her. “It’s unstable.” Sure, whatever.

I’m not saying I “understand” that scene. But I can appreciate it as a nearly pure moment of odd theater and tuck it away in my memory and hope some day I can make sense of it.

“Lost” has walked a fine line between the mysterious and the merely baffling. And it has never toppled over into the pretentious or become weird just for the sake of being weird. I don’t care if it ends up being a vision of hell or Hurley’s hallucination. I’m hooked for the duration.

On tonight’s two episodes: Locke enlists Sawyer (8 p.m.), Ben confides in Locke as Juliet’s secrets are revealed (9 p.m.).

¢ “The Dropout Chronicles” (7:30 p.m., MTV2) looks at three high school students on the verge of walking away from school. All three seem plagued by a disinterest in academics, unambitious peers, unrealistic goals and a steady supply of unproductive distractions. (Like watching MTV!)

Tonight’s other highlights

¢ A cadaver projects a certain glow on “Bones” (7 p.m., Fox).

¢ Four minus one equals three on “American Idol” (8 p.m., Fox).

¢ John McEnroe (as himself) becomes a suspect on “CSI: NY” (9 p.m., CBS).