The Carrie Diaries (8pm, CW) - Carrie attends a Halloween bash in the city and brings Walt along, while Maggie and Mouse go to Sebastian's Halloween party in order to keep tabs on him.
How I Met Your Mother (8pm, CBS) - Barney discovers a lost episode of a behind-the-music show that features Canadian teen singing sensation Robin Sparkles (Cobie Smulders, right) and includes a new video and another intriguing revelation from her past.
The Following (9pm, Fox) - Hardy and the team try to predict the actions of one of Carroll's followers. Meanwhile, Paul has difficulty controlling his jealousy over Emma and Jacob's relationship, and the origin of Hardy and Carroll's relationship is revealed.
Bunheads (9pm, ABC Family) - Fanny is angry after Milly starts to dictate how she should run an upcoming dance recital. Also, Scotty and Michelle go on a road trip that involves a surprise detour.
Monday Mornings (10pm, TNT) - A new drama executive produced by David E. Kelley and Dr. Sanjay Gupta, about the personal and professional lives of doctors at a Portland, Ore., hospital. In tonight's premiere, Jorge Villanueva (Ving Rhames) treats a car-crash victim and Dr. Ty Wilson helps a young boy with a soccer injury. Read Adrienne's "Monday Mornings" review.
Castle (10pm, ABC) - Castle and Beckett discover evidence that links a senator to a young woman's murder.