FINALE WATCH: “Fringe” (Fox at 9 p.m.). Status: Renewed for a fourth season. Ratings haven’t been spectacular for this sci-fi drama, but coupled with low expectations on Friday nights, this drama will live on. Meanwhile, Fox promises a “climactic” close to the season, as Peter finally confronts his destiny and another team member doesn’t get so lucky.

Canadian cop drama “Flashpoint” (CBS at 8) returns for Season 4, as a man charged with killing his baby escapes from prison, leaving the Strategic Response Unit to chase him.

Chef Ramsay heads to Eagle Rock, Calif., on “Kitchen Nightmares” (Fox at 8) to try to keep an Italian restaurant from falling apart.

What’s it like to be Clark Kent for a day? Lois finds out right before the wedding, as Jor-El gives her Clark’s superpowers temporarily, just for fun — sadly, it means she must go up against a villain on “Smallville” (CW at 8).

“Primetime: What Would You Do?” (ABC at 9) continues to test random people with bizarre scenarios, including a woman lying about being a supermodel to her (literally) blind date and another person openly tasting items in the supermarket produce aisle.

Howard University student Ionnie McNeill, known as the “Baby Billionaire,” shares advice on how people can start investing at an early age on “Biz Kid$” (WETA Kids at 9), a financial literacy show aimed at young ones.

Shark tanks, feather skirts . . . all of the ceremonies on “Four Weddings” (TLC at 10) have unique twists, including one in which the bride helps make her dress.

Singer Steven Tyler visits “The Tonight Show With Jay Leno” (NBC at 11:35), along with actress Aubrey Plaza and musical guest the Civil Wars.

“Late Show With David Letterman” (CBS at 11:35) hosts actor Bill Murray, comedian Mike Birbiglia, musical guests Brother and a demonstration by Brian Miser, known as the “Human Fuse.”

— Emily Yahr