“Lost” (8 p.m., ABC) remains much more than the sum of its parts. Just when it seems too much like a geeky science-fiction series or risks sinking in a supernatural gumbo, the soap-opera aspects take over.

Named for famous characters from the worlds of science and philosophy, John Locke, Daniel Faraday, Benjamin Linus, Richard Alpert and Desmond Hume best represent the show’s cerebral core and mind-bending overtones. Whether their names are clues or merely intellectual red herrings hardly seems to matter.

And just when we begin to think too hard about all that, the good-looking Jack, Kate, Sawyer and Juliet provide the overlapping soap-opera love interest.

But it’s Hurley who keeps the show grounded. Simple yet insightful, Hurley’s worldview is shaped almost entirely by pop culture. He spends his time “creating” and improving on “The Empire Strikes Back.” To him, Faraday’s trip back to 1954 translates to “like Fonzi times.” He’s also the character the writers rely on to try to make sense of the show’s elaborate plot and the characters’ strange predicament.

His tearful explanation of his story to his mother earlier this season was both poignant and hilarious. More recently, he encouraged Miles to spend time with his real father, Dr. Chang, as well the baby who was in fact, the infant Miles. “Dude, you could change your own diaper.”

Lost in the fantasies of “Star Wars” and other adventures, Hurley seems best able to absorb or deflect the baffling plot twists. He’s also a reminder that, for all of its intricacies, “Lost” is pure pop culture and great pop culture — the kind that future Hurleys will be discussing and dissecting for decades to come.

• Based on documents and transcripts that have come to light only since the collapse of the Soviet Union, the three-part series “WWII Behind Closed Doors: Stalin, the Nazis and the West” (8 p.m., PBS, check local listings) mixes movie-worthy dramatic reenactments with period footage and recent interviews to offer new insights into the diplomatic history of World War II.

Part 1 begins with the 1939 pact between existential rivals Nazi Germany and the U.S.S.R. We learn that the Soviets, particularly Stalin, were far more eager to cooperate and aid the Germans than previously revealed. Over the next two Wednesdays, “WWII” will follow the uneasy cooperation between wartime allies America, Britain and the U.S.S.R. Look for Bob Gunton, who played the recently deposed chief of staff on “24,” as President Franklin D. Roosevelt.

Tonight’s other highlights

• A secret shame rocks a political dynasty on “Law & Order: Criminal Intent” (7 p.m., NBC).

• A serial offender proves elusive on “Lie to Me” (7 p.m., Fox).

• J.D. departs on the season finale of “Scrubs” (7 p.m., ABC).

• “Ratzilla” (7 p.m., Animal Planet) looks at reports of giant rodents in New Jersey and Florida.

• Daughtry and No Doubt perform on “American Idol” (8 p.m., Fox).

• Ricki Lake examines natural childbirth in the documentary “The Business of Being Born” (8 p.m., Showtime).

• The wrong man goes behind bars on “CSI: NY” (9 p.m., CBS).