Percy (Xander Berkeley) continues his plan to take back Division by threatening to kill Nikita's (Maggie Q) mentor Carla (guest star Erica Gimpel, "Fame"), the woman who took Nikita off the streets when she was a junkie. Determined to get to Carla before Percy, Nikita uses Madeline (guest star Alberta Watson) to send her a message. Percy intercepts the message and it's a race to see who can get to Carla first. Meanwhile, Amanda (Melinda Clarke) tells Alex (Lyndsy Fonseca) it's time for her to take back Zetrov and reveal to the world that Alexandra Udinov is alive. Shane West and Aaron Stanford also star. Brad Turner directed the episode written by Carlos Coto.

CLOWNS, UNICORNS AND SHARKS, OH MY! - Sam is forced to confront a childhood fear when a case takes him and Dean to Kansas to investigate Plucky Pennywhistle's Magical Menagerie, a local pizza chain that hosts children's birthday parties. Sam and Dean discover that the victims' children had recently been to the restaurant and drawn a picture of their worst fear, which then came to life to kill their parent. While Dean confronts the man behind the magic, Sam is left to deal with some very angry clowns. Mike Rohl directed the episode written by Andrew Dabb & Daniel Loflin

NATE THROWS A VALENTINE'S DAY BASH / ST. VINCENT PERFORMS - It's Valentine's Day on the Upper East Side and Blair can't resist playing cupid for someone she loves. Georgina is intent on stirring up more drama, so she decides to crash Nate's Valentine's Day party. Meanwhile, Serena is shocked by something she witnesses at the party. Penn Badgley, Ed Westwick, Kaylee DeFer, Kelly Rutherford and Matthew Settle also star. Matt Penn directed the episode written by Austin Winsberg.

LEMON AGREES TO DRESS UP AS JOELLE TO HELP OUT WADE - Wade (Wilson Bethel) somehow convinces Lemon (Jaime King) to dress up as Joelle (guest star Courtney Parks) as part of a scheme to convince Joelle's ex-boyfriend (guest star Ted Welch) that he didn't actually see Wade and Joelle together. Lavon (Cress Williams) asks Zoe (Rachel Bilson) to help him figure out why Didi (guest star Nadine Velazquez) has been avoiding him, but once Zoe uncovers the shocking reason she isn't quite sure what to do with the information. George (Scott Porter) comes to Zoe for advice in determining whether there is a medical explanation for the behavior of one of his clients. Tom Amandes directed the episode written by Debra Fordham.

BLUEBELL PREPARES FOR THE ANNUAL SWEETIE PIE DANCE - Zoe (Rachel Bilson) decides that it's too soon in her relationship with Judson (guest star Wes Brown) to go to the annual Sweetie Pie Dance so instead she makes plans to have a sleepover with Rose (McKaley Miller), whose parents are going out of town. George (Scott Porter) misplaces the save the dates for his upcoming wedding which causes major trouble in Lemon (Jaime King) paradise. Lemon wants her father (Tim Matheson) to finally move on from her mother leaving him, so she secretly gets him a date for the dance. Wilson Bethel and Cress Williams also star. Patrick Norris directed the episode written by executive producer Leila Gerstein.