Vice President Joe Biden and Rep. Paul Ryan face off at Centre College at Danville, Ky. In the one-and-only vice presidential debate (7 p.m., Channels 2, 4, 5, 7, 13, CNBC, CNN, C-SPAN, FNC, FBN, MSNBC).
Because, really, do we need more than one vice presidential debate?
What The Vampire Diaries (7 p.m., CW/Ch. 30) needed was one more vampire. So in the fourth-season premiere, Elena wakes up after the accident and discovers she's growing fangs.
Like it or not, she's got to feed, or there will be one less vampire.
And what nobody needs is a reboot of Beauty and the Beast (8 p.m., CW/Ch. 30). At least not this reboot.
It's sooooo bad it's funny. And it's not supposed to be.
Elsewhere on TV ...
Baseball playoffs: San Francisco Giants at Cincinnati Reds - Game 5 (11 a.m., TBS); St. Louis Cardinals at Washington Nationals - Game 4 (2 p.m., TBS); Detroit Tigers at Oakland A's - Game 5 (7:30 p.m., TNT)
NFL (6 p.m., NFL Network): Pittsburgh Steelers at Tennessee Titans
High school football (7 p.m., Ch. 14): West Jordan at Alta
Women's college soccer (7 p.m., BYUtv): San Francisco at BYU
Project Runway (7 and 11:01 p.m., Lifetime): In Part 1 of the season finale, Tim Gunn visits the finalists at their homes.
The X Factor (8:30 p.m., Fox/Ch. 13): Contestants visit mentors' homes.
The Big Bang Theory (9 p.m., CBS/Ch. 2): Amy doesn't like Sheldon's new assistant.
Last Resort (9 p.m., ABC/Ch. 4): Marcus and the crew search for three missing members.
30 Rock (9 p.m., NBC/Ch. 5): Liz and Jack fight over political satire on thee show.
Two and a Half Men (9:30 p.m., CBS/Ch. 2): Alan and Lyndsey try to spice up their relationship.
Up All Night (9:30 p.m., NBC/Ch. 5): Chris runs into an obnoxious former college classmate.
It's Always Sunny in Philadelphia (11 p.m. FX): Dennis and Dee are faced with a decision about pulling the plug on their grandfather - who, it turns out, is a former Nazi. (Season premiere)
The League (11:30 p.m., FX): The season premiere of this highly annoying, unfunny show.
Brand X (midnight, FX): A second season begins.