At the Snowflake dance, Blair and Chuck discover their lookalikes hooking up. Aaron's ex Lexi flirts with Dan, causing trouble with Serena. Nate, Jenny and Vanessa get into a messy love triangle that involves a stolen letter and a revealing dress. Bart Bass suffers a car accident on his way to the ball.
Cameron learns that a terminator was accidentally sent back to 1920s Los Angeles, and she tries to find out what happened to him. Meanwhile, John has a run-in with a group of punks while taking Riley home from a party.
The team is assigned to survey the Global Launch Agency, when intel shows that someone might penetrate their security. During the surveillance someone intrudes the lab who turns out to be Casey's former sensei Ty Bennett. Meanwhile, Captain Awesome's perfect parents decide to pay Devon and Ellie a surprise visit to help them plan the wedding, and Emmett Milbarge introduces an "Employee of the Month" contest to the Buy More, but the employees start their own contest instead.
When Denny receives bad news about the state of his Alzheimer's, Alan goes before the Massachusetts Supreme Court to plead for access to an experimental drug that could help his condition. Meanwhile, Jerry and Katie try to help a girl get into Harvard after her SAT scores arouse suspicion, and Catherine Piper returns.
Roy and Maggie loved their house from the moment they saw it. But after raising three boys and starting their own business, their family has outgrown the space - especially when it comes to storage. Realtor David and Designer Hilary are ready to help. David will look for houses to fit their family while Hilary will renovate their home hoping to convince them to love it again. In the end, Roy and Maggie will have to choose what to do with their house. Will they Love It Or List It?
Audrina tries to make amends with Lauren after the fall-out. Then it's off to Nana's house where Spencer and Stephanie compete for their grandmother's affection.
Lebano leads his associates on a brutal campaign to wipe out their rivals in Rome - but after forming an alliance with the Sicilian mafia, they become entangled in a terrorist plot to kidnap one of Italy's most senior politicians. Meanwhile, Scialoja grows dangerously close to Patrizia and Ice continues his romance with Roberta.
Mrs Wormwood returns to see Sarah Jane- but to ask help. The Bane have turned against Mrs Wormwood and are preparing to unleash a dark power against the universe. However, to thwart the Bane's plan, Sarah Jane must call upon an old friend
When Drinky Crow's girlfriend dies horribly, he decides to convert his grief into money at a marine theme park that specializes in sex, violence, and meta-humor.
Stan emcees a CIA telethon to raise funds for the agency's torture budget after Congress slashed it. But Roger is out to sabotage it because Stan stole the idea for it from him.
In the middle of a heat wave, a cattle truck loaded with thirsty and overheated horses pulls into Heartland. Ty can hardly believe his eyes when the driver turns out to be his dad.
Nora recruits the family to deconstruct her new charity money pit; Kitty & Robert take a huge & overwhelming step in adoption; Sarah takes a big risk with her new business partners by eating crows; Holly pushes Tommy to his limits when she does something in the winery without consulting him.
Spinner and Jane have plans for next year - she'll start pre-law and he'll attend police college. When he doesn't get in, he can't bear to tell her, so he lies. Jane catches him and starts to wonder if her future includes him. Clare gets invited to the dance by both K.C. and Connor. When it looks like their struggle for her attention will jeopardize Robot Wars, she decides to go with neither. Alli gets an anonymous rose but after asking Anya who it was, she reveals that is was Johnny who sent her the rose. When Alli asks Johnny to the Valentine's dance, he rejects her saying he can't go with her because she is a "niner" and his friends will tease him. Meanwhile, Kelly and Emma reveal their feelings for each other and go on a date.
Hank tries to help Bobby become a member of the Order of the Straight Arrow, but he disagrees with the "Arrowmaster" who is a new member of Arlen. Meanwhile, Peggy gets involved in the disagreement as she is the local Welcome Wagon representative.
For Gaby and Carlos, injuries sustained in the fire lead to a fortunate discovery. But for most, the consequences are less forgiving. Lynette and Tom vow to protect son Porter at any cost. Susan must learn to let go of the man she loves. Orson's attempt at a good night's sleep puts Bree in a most precarious, though amusing, position on the day of her big cooking demonstration.
The team's attempts to raid an anthrax lab are thwarted by an official from the Department of Defense (Michael McKean), who believes his high-tech intelligence is superior to field logic.
A series of chess-like moves ensues when Dexter and Miguel vie for the upper hand, with Miguel winning Rita's affection by presenting her with a lavish wedding gift. Elsewhere, Debra wonders if her relationship with Anton is worth the trouble.