Presenting three overlapping stories, “Modern Family” (8 p.m., ABC) combines the edgy and knowing with the warm and even sentimental. That’s the hardest sitcom trick to pull off. But when it works, it’s the most rewarding.

Ed O’Neill stands out as the much older and seemingly exhausted husband of a stereotyped Latin spitfire (Sofia Vergara). A second family features Claire (Julie Bowen), a harried mom who seethes in resentment at her husband Phil’s (Ty Burrell) laid-back parenting style. Phil has the best scenes as the delusional dad who truly believes that his kids think he’s cool.

A third family profile concerns two gay men, the fussy Mitchell (Jesse Tyler Ferguson) and the exuberant Cameron (Eric Stonestreet), who are bringing their adopted baby home for the first time. Both reflect a layering of stereotypes, played with great timing. Mitchell is enough of a control freak to know that he’s perceived as such and is given to spot-on lines like “We need to stop knowing people named Andre.”

The stories converge rather sweetly at the end of a very accomplished pilot that should have viewers coming back for more.

• Like the promising “Nurse Betty” and forgettable “Hawthorne,” the new series “Mercy” (7 p.m., NBC) features a street-smart nurse who knows more than the doctors and isn’t afraid to confront them with their cowardice and incompetence.

Taylor Schilling stars as nurse Veronica Callahan, a woman still reeling from her service in Iraq. In the opening moments, she experiences a violent flashback and then saves a car-accident victim with battlefield procedures.

Then the show shifts gears to offer standard medical-soap-opera fare, with a few nods to a messy New Jersey family life fueled by alcoholism and the rather low expectations that she settle down with the working stiff she married. Only she’s really still in love with a doctor she met in a war zone who has just to relocate to Mercy Hospital. “Mercy” will be on “Do Not Resuscitate” soon enough.

• “Eastwick” (9 p.m., ABC) adds an occult dimension to the cutesy-pie “Desperate Housewives” take on suburban women with something extra. Three photogenic small-town residents (Rebecca Romijn, Lindsay Price and Jaime Ray Newman) discover a secret bond of special powers after a mysterious stranger, Daryl Van Horne (Paul Gross), moves to town. But why does he look as if he just walked off the set of “Dynasty”? Rather weak Ouija.

• “Cougar Town” (8:30 p.m., ABC) continues the “Sex and the City” trend of blending tales of female sexual empowerment with brazenly witless dialogue. It wastes the talents of capable performers, including Courteney Cox (“Friends”), Busy Philipps (“Freaks and Geeks”) and Dan Byrd (“Aliens in America”).

As the title implies, “Cougar” is all about frisky women of a certain age and their young conquests. Yet in this show’s rather unsteady hands, this phenomenon seems more like a bout of mental illness than personal liberation. Put this cat down.

Tonight’s season premieres

• Barb’s visa woes on “The New Adventures of Old Christine” (7 p.m., CBS).

• A pep talk from Dad on “Gary Unmarried” (7:30 p.m., CBS).

• Hotcher vanishes on “Criminal Minds” (8 p.m., CBS).

• Nate makes an effort on “Law & Order: Special Victims Unit” (8 p.m., NBC).