‘CSI’ Finale, ‘Welcome to Earth,’ CMT Christmas Specials, Chicago Shows Take a Break

CSI: Vegas

The season-long arc concludes with Gil Grissom (William Petersen) and Sara Sidle (Jorja Fox) desperately looking for any evidence that might clear their former lab partner David Hodges (Wallace Langham), who has gone missing mid-trial. If the case goes south, the reputation of the crime lab established over 15 previous seasons could be ruined. We’ve all watched enough TV to know the odds of that happening. (The odds of CSI: Vegas, originally announced as an “event series,” returning are less certain.)

Welcome to Earth

Currently riding a wave of Oscar buzz for his role in King Richard, Will Smith travels the world in a visually spectacular six-episode series from National Geographic. With elite explorers to guide him on a journey to some of the planet’s most extreme and remote locations, he rappels down a volcano, kayaks through rapids, witnesses animal swarms, with each stop offering an adventure most of us can only dream of.

CMT Crossroads

The first-ever Christmas-themed Crossroads episode welcomes back Brett Young, collaborating with the likes of Boyz II Men, Darius Rucker, Colbie Caillat and Gavin DeGraw on seasonal favorites from his first holiday album, “Brett Young & Friends Sing the Christmas Classics.” Followed by CMT’s A Tennessee Kind of Christmas (9/8c), where country greats including Amy Grant, Billy Ray Cyrus, Wynonna, Pam Tillis, Steve Wariner and more perform Christmas chestnuts from venues in and around Nashville while sharing their holiday traditions and memories.

Chicago Fire

On a night of midseason finales, the long-running first-responder drama marks its first Christmas without Casey, but there’s optimism among the Firehouse 51 crew as Gallo (Alberto Rosende), Ritter (Daniel Kyri) and Violet (Hanako Greensmith) introduce their microbrewery side hustle at Winterfest. The mood is a bit more somber on Chicago Med (8/7c) as Will (Nick Gehlfuss) works with Dylan (Guy Lockard) to save a 4-month-old while fretting over the outcome of his ethics investigation. On Chicago PD (10/9c), Voight (Jason Beghe) and Halstead (Jesse Lee Soffer) sweat out the FBI closing in on the Roy Walton investigation. Happy holidays, all.

Inside Wednesday TV:

• Christmas with a Crown (8/7c, Lifetime): This checks off just about every Christmas-movie box: Lisa Durupt is Cassie, who returns to her hometown (check) to revive her family’s traditional Christmas festival (check), when she falls for a visiting prince (Marcus Rosner) in disguise (double check) who’s gone incognito to discover the true meaning of Christmas (final check).
• Christmas Around the World (8/7c, The CW): A two-hour special traverses the globe to sample regional holiday events including a stroll through Dickens’ London, a “Santa on the Run” event in Australia, indoor skiing in Dubai and communing with penguins in South Africa.
• Tough as Nails (9/8c, CBS): The Season 3 finale puts the finalists through one last series of rigorous challenges to decide who’ll take home the $200,000 prize.
• Alter Ego (9/8c, Fox): In another season finale, the final four avatars compete for championship bragging rights.
• Dr. Pimple Popper: A Pimple Carol (10/9c, TLC): A special holiday edition finds dermatologist Dr. Sandra Lee helping patients get party-ready complexions.
• It’s Always Sunny in Philadelphia (10/9c, FXX): Travel back to the more innocent 1990s as the gang hangs out at the roller rink, considering their hopeful futures. (If only they knew.) Then it’s back to the present day in an episode titled “The Gang Replaces Dee with a Monkey,” as the guys seek a new co-worker when they suspect Dee (Kaitlin Olson) is menopausal.