What to Watch on Thursday: Hilary Duff turns Abed into a "mean girl"

Vampire Diaries (8pm, CW) - Elena is abducted by a masked stranger at the masquerade ball, and Stefan and Damon learn surprising information about vampires in the distant past. Meanwhile, Jeremy helps Bonnie after she cast an exhausting spell, and Caroline tries to make life easier for Tyler now that he is werewolf.

Community (8pm, NBC) - Abed becomes a "mean girl" to the delight of Britta, Shirley, and Annie, whose encounter with a cruel classmate (Hilary Duff) leaves them reeling. Elsewhere, Jeff and Troy find a hidden trampoline, which provides the duo a spiritual enlightenment. The change in their personalities doesn't go unnoticed, and Pierce becomes determined to learn their secret.

Fringe (9pm, Fox) - A security breach in the parallel universe attracts the Fringe Division's attention after a man frees his twin brother from a quarantined amber area. Meanwhile, Secretary Bishop observes the effects of sensory deprivation on Olivia, who continues to have visions of Peter.

The Fairy Jobmother (9pm, Lifetime) - Hayley helps an unemployed pair with four children who lost their home to Hurricane Katrina.

Private Practice (10pm, ABC) - The doctors come to Charlotte's aid when she's found bloodied and bruised in a hospital hallway after she's attacked by a deranged man (Nicholas Brendon) in the ER.