There's also the uneasy knowledge that when Lea Michele's character, Rachel, cries over boyfriend Finn, it mirrors the actress' grief over losing her off-screen romantic partner. She dedicated her recent Teen Choice Award to Monteith, accepting with tears and wearing a necklace that spelled out "Cory."
Any real loss is difficult to cope with in the framework of fiction. But the deaths of sitcom stars John Ritter of "8 Simple Rules for Dating my Teenage Daughter" in 2003 and that in 1985 of Nicholas Colasanto, the bartender nicknamed Coach in "Cheers," were illness-related and less fraught in their translation to on-air tributes.
Some observers have suggested that the "Glee" episode should treat Monteith with dignity but not ignore the scourge of addiction that cut short his life — especially on a series that's regularly delivered life lessons on big topics such as tolerance within its song-filled framework.
Last month's Emmy Awards remembered Monteith, with "Glee" star Jane Lynch calling his death a "tragic reminder of the rapacious, senseless destruction that is brought on by addiction."
"Glee" creator Ryan Murphy has not offered detailed plans for the episode, but has said that drugs will not be the cause of Finn's death.
However, Fox Chairman Kevin Reilly told members of the Television Critics Association last August that the episode would deal with "the incidents involved in Cory's passing and the drug abuse in particular," and that public service announcements involving cast members would air with it.
One such announcement is planned, Fox said Tuesday.
Mike O'Malley, who played stepdad Kurt Hummel to Monteith's Finn, offered his take on the issue.
"He dies of cancer, in a car accident, he dies of old age, he dies because of a drug overdose. It doesn't matter," O'Malley said. "He's gone and you're never going to see him again, and so now you gotta go to work, you got to honor his life, you're trying to honor his fans' relationship with the character."
He said the episode included "the most emotional scene I've ever acted in my entire life," and called Monteith "a real bright light."
In a Fox promotion for the episode titled "The Quarterback," students are seen gathered at an ad hoc memorial display at Finn's high school locker, while another scene shows a weeping Rachel being comforted by glee club teacher Will (Matthew Morrison).
A mournful version of Bob Dylan's "Make You Feel My Love" performed by Michele is heard on the promo soundtrack. Other songs in the episode include covers of "Seasons of Love" from the Broadway musical "Rent"; James Taylor's "Fire & Rain"; The Pretenders' "I'll Stand by You"; The Band Perry's "If I Die Young" and Bruce Springsteen's "No Surrender."
"Glee" will take a break of several weeks after the Monteith tribute as the network airs baseball's World Series.
AP reporter Lauri Neff in New York contributed to this report.