When it comes to spy thrillers, there’s no place like home. Now entering the home stretch of an impressive first season, “The Americans” (9 p.m., FX) is the latest show to re-emphasize that old adage from “The Wizard of Oz.”

”The Americans” puts an almost suffocating emphasis on home and family. Philip Jennings (Matthew Rhys) and Elizabeth Jennings (Keri Russell) are KGB agents passing as average Americans circa 1981. They have managed to raise a “real” family as part of their assigned arrangement. Sex and subterfuge are part of their secret job for the Soviet Union, but Philip’s relationship with one American has caused collateral damage to the couple’s emotional Potemkin village. So the spies decide to foist a “real” separation on their fake marriage, much to the dismay of their actual children. It’s all a bit difficult to follow — or swallow.

It doesn’t help matters that “The Americans” relies, like sitcoms of old, on an ever-present nosy neighbor, Stan Beeman (Noah Emmerich), who happens to be an FBI agent fishing in the same small pond of spies and counterspies as Philip and Elizabeth. It’s beyond believable that agents for both sides would get together over casseroles in Stan’s kitchen and then fail to recognize one another scant days later because of a few wigs and costume changes.

Don’t get me wrong; “The Americans” is a smart show well worth watching. But as with “24,” the all-in-the-family tension and the sheer number of coincidences and chance encounters are beginning to border on camp.

Tonight’s other highlights:

• Finalists perform on a two-hour “American Idol” (7 p.m., Fox).

• Oliver asks McKenna out on a date on “Arrow” (7 p.m., CW).

• The detectives help investigate a man suspected of being a serial killer on “Law & Order: Special Victims Unit” (8 p.m., NBC).

• An easy real estate “flip” just won’t move on “Modern Family” (8 p.m., ABC).

• Gene Simmons has a special request on the second season premiere of “Toy Hunter” (8 p.m., Travel).

• A triple homicide leaves few clues on “CSI” (9 p.m., CBS).

• A sudden crisis forces Rayna to skip a New York concert date on “Nashville” (9 p.m., ABC).