“Supernatural” (7 p.m. and 8 p.m., CW) wraps up its season with Sam and Dean facing the forces of Hell, or some nasty netherworld, as they do on a regular basis. While “Smallville” has been packed away in the Fortress of Solitude where all old series go, “Supernatural” remains on the schedule for next season.

Also ending tonight and returning next season is Fox’s “Kitchen Nightmares” (7 p.m., Fox). A repeat “Nightmares” (8 p.m.) follows.

As I file this column, every network but CBS has announced their complete schedule for next season. So the fate of “Blue Bloods” has yet to be announced. Like many CBS series, “Bloods” attracts an audience of older viewers, not the most attractive to advertisers. Friday nights used to belong to network series appealing to young viewers, but those shows, and their audience, have migrated to places like Nickelodeon and the Disney Channel where “iCarly” (7 p.m., Nickelodeon) and “Lemonade Mouth” (7 p.m., Disney) reign supreme.

As it has for some years now, Friday nights will become a last-chance perch for shows that have barely escaped cancellation. Look for NBC’s “Chuck” to move to Friday’s next fall. “Fringe” returns to Fox Fridays in autumn as well as “Kitchen Nightmares.” ABC will move its Sunday night staple “Extreme Makeover: Home Edition” to Friday evenings, where it will join “Shark Tank.”

NBC will debut one new series “GRIMM” on Friday nights, a detective series inspired by the supernatural creatures of the classic Grimm’s Fairy Tale. New network series have the hardest time of finding an audience on Friday nights, so we’re not sure if that show will live happily ever after.

• “Children of Promise: The Legacy of Robert F. Kennedy” (7 p.m., Discovery ID) documents the Children’s Defense Fund, a private charity established in memory of the slain senator, designed to intervene in the lives of at-risk children and teens. Over the decades, the Massachusetts non-profit has become a model agency, helping youth destined for a life of violence and crime finish school, get jobs and star families.

• According to one radio and television preacher, the end of the world is scheduled for tomorrow, May 21. Animal Planet is the perfect place to get in the mood, with two helpings of epidemic documentaries “Killer Outbreaks” (7 p.m. and 8 p.m., Animal Planet) and a real feel-bad special called “Bed Bug Apocalypse” (9 p.m.). Sweet Dreams.

Tonight’s other highlights

• Spike suspects his old colleague of the worst on “Flashpoint” (7 p.m., CBS).

• A magazine praises Coach Taylor “Friday Night Lights” (7 p.m., NBC).

• Just when you thought it was over, “Prince William & Catherine: A Royal Love Story” (7 p.m., OWN) meditates on a “people’s princess.”

• Four finalists help out at a food pantry at a disaster site on “CMT’s Next Superstar” (8 p.m., CMT).

• “20/20” (9 p.m., ABC) puts infomercial claims to the test.

• People, gorillas and turtles test the boy’s mettle on “Swamp Brothers” (9 p.m., Discovery).