The Vampire Diaries (8pm, CW) - Connor attempts to uncover town secrets and tries to convince Jeremy to help him. Meanwhile, Elena finds it difficult to control her anger when Rebekah arrives at school.
Big Bang Theory (8pm, CBS) - Leonard tries a scientific approach to seducing Penny. Former astronaut Buzz Aldrin has a cameo.
30 Rock (8pm, NBC) - Liz and Jack square off in a political battle to influence voters in the 2012 presidential election.
Person of Interest (9pm, CBS) - Reese and Finch face an ethical dilemma when the Machine gives them the number of a mob enforcer who's in danger.
Parks and Recreation (9:30pm, NBC) - Halloween brings some upsetting news for Leslie in the form of a job offer for Ben. At the same time, Ron (Nick Offerman, left) and Andy go trick-or-treating with Diane's (Lucy Lawless, left) daughters, while Tom looks for a new business venture.
Scandal (10pm, ABC) - The parents of a missing college student seek help from the firm, while David gets unexpected assistance with a case he's investigating. Also, Mellie wields her political influence, creating tension for Fritz.
Elementary (10pm, CBS) - A Wall Street executive dies from an apparent heroin overdose, but Holmes isn't convinced. Meanwhile, Watson starts dating again.