Joe Mantegna and the Criminal Minds Team Take One Last Run at The Chameleon

Criminal Minds signs off tonight with back-to-back episodes that promise to bring back departed cast members and tie up loose ends. Elsewhere across the dial, the leading Democratic Presidential candidates hit the debate stage in Nevada, Survivor moves forward with its warring past winners, and Masked Singer welcomes its second competitors to the stage. Here's what's new and noteworth on TV this Wednesday.

SERIES FINALE: After fifteen seasons, Criminal Minds is coming to an end with a two-part finale. The first hour will see David Rossi (Joe Mantegna) leading his team in a final attempt to capture Everett Lynch (Michael Mosley) aka The Chameleon. In part two, following an encounter with Lynch, Dr. Reid (Matthew Gray Gubler) will suffer a head injury and see visions of people from his past — and you know what that means. Watch the preview. 9:00 PM ET on CBS

LIVE DEBATE: Mike Bloomberg is likely to be taking fire from all sides tonight as the former New York mayor who's seen a recent surge in the polls takes the stage at his first Democratic Presidential Debate in Nevada. The other qualifying candidates are Joe Biden, Pete Buttigieg, Amy Klobuchar, Bernie Sanders and Elizabeth Warren. 9:00 PM ET/6:00 PM PT on MSNBC

NEW EPISODE: Now that Survivor: Winners at War is underway, the competition is starting to get ugly. Tonight finds one of the castaways set on revenge after a close ally was sent to the Edge of Extinction in one of the season's many possible twists. Watch the preview. 8:00 PM ET on CBS

NEW EPISODE: Six new stars hit the The Masked Singer stage as host Nick Cannon and panelists Ken Jeong, Jenny McCarthy, Nicole Scherzinger and Robin Thicke welcome Group B to the competition. 8:00 PM ET on Fox

COMEDY SPECIAL: Filmed at Montreal's Just for Laughs Festival, Howie Mandel's 5th Annual All-Star Comedy Gala features appearances by Rachel Bloom, Alonzo Bodden, Ronny Chieng, Cameron Esposito, Fortune Feimster, Anjelah Johnson and more. Watch the preview. 8:00 PM ET on The CW

NEW EPISODE: Dex (Cobie Smulders) looks into plagiarism accusations on an all new Stumptown. Meanwhile, Tookie (Adrian Martinez) hosts a birthday party at The Bad Alibi. 10:00 PM ET on ABC

SERIES PREMIERE: Primetimer favorite Matt Berry stars as Detective Inspector Rabbit in Year of the Rabbit. The six episode period police comedy has already been renewed for a second season. Watch the preview. 10:30 PM ET on IFC

SEASON PREMIERE: Jon Favreau and Roy Choi are back with fresh installments of The Chef Show. Guests include Wolfgang Puck and Spider-Man's Sam Raimi.. Streaming on Netflix

Mike Attebery is Senior Editor at Primetimer and the author of seven mystery thrillers. Follow him on Twitter at @mikeattebery.