In the spirit of Valentine's Day, Meredith and Derek try to have a night to themselves when Lexie offers to watch Zola; Callie hands babysitting duties over to Mark so that she can surprise Arizona with a romantic evening; and Ben proves to Bailey that he knows her better than she thinks. Meanwhile, the ER fills with romantics, including a 10-year-old girl who has an allergic reaction to chocolates from her valentine and a man who is hit by a car while chasing down his frustrated girlfriend.
In honor of the holiday, Faye and Melissa throw a girls only anti-Valentine’s Day slumber party for themselves and fellow witches Diana and Cassie. But the night gets wilder than expected when Melissa offers Diana some mood altering “Devil’s Spirit” and the first person Diana loosens up around is Lee, who crashes the party to help Faye achieve her own power. Meanwhile, Cassie is forced to turn to Adam and Jake after she becomes haunted by the spirits of some vengeful witches.
When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.
Criss and Liz decide to celebrate Valentine's Day, but they need to buy a dining room table first. Jack entertains his mother-in-law, Diana, as Jenna frantically looks to Pete to fill in last-minute as the producer of her first live performance on "America's Kidz Got Singing." Back at the office, Tracy and Frank try to help Lutz find someone to spend Valentine's with.
While a jury deliberates the guilt or innocence of a defendant on trial for murder, Jane tries to prove she has been wrongfully accused before time runs out. Meanwhile, Summer may have gone too far when she helps Cho make a case against a suspect.
Elena is surprised to receive an invitation to a formal ball, and when Damon and Stefan hear the party is being hosted at Klaus’s newly renovated mansion, they both insist on attending the event with her. Caroline and Matt also receive invitations to the ball from unexpected admirers. At the elegant party, Elena learns of a horrifying plan that could lead to numerous deaths and she must decide who she can trust with her new information. Caroline discovers a side of Klaus no one would have suspected. Finally, after an evening of violence and dashed hopes, Damon finds a new way to cope.
Criss and Liz decide to celebrate Valentine's Day, but they need to buy a dining room table first. Jack entertains his mother-in-law, Diana, as Jenna frantically looks to Pete to fill in last-minute as the producer of her first live performance on "America's Kidz Got Singing." Back at the office, Tracy and Frank try to help Lutz find someone to spend Valentine's with.
Dwight scores a special assignment at Sabre's Florida headquarters. As a result, he and Andy must decide which Scranton staffers will join him. Elsewhere, Pam returns from maternity leave.
Historian Saul David explores how wars are really fought - in the backroom of military planning. He shows how generals have met the challenge of moving armies.
Sam finds his estranged sister, Corinne, in jail, heavily medicated and near-catatonic, and brings her to Sheldon for help; Erica begins secret treatments for her cancer and refuses to let Cooper and Charlotte tell Mason; Cooper, Pete and Addison treat the baby of a drug addict; and things between Violet and Scott continue to heat up in the bedroom.
When Ava and Kevin have an epic blow-out, Reagan and Chris find themselves wistful for relationship drama and unintentionally end up creating some of their own.
The eight remaining All Stars compete head to head fin a sportswear challenge for one of the four seasons. Guest judge Cynthia Rowley.
An amateur magician's (Jonathan Slavin) assistant vanishes during an ambitious disappearing act; Leo asks Isabel for help finding Willa.
Jason quits his job and hopes to network at a party hosted by James Franco; Tina questions whether she's ready to date Brett; Stacey and Eric find themselves in a foursome.
Installing windows using a custom copper pan for flashing; installing architectural shingles.
Marcus finds a man to provide guns for the job, but needs cash to prove they are serious.
The Hollywood Round continues as Randy, Jennifer and Steven narrow down the contestants after listening to the Group Round Performances.
Following the events of last Friday Lee is going to see the Dudes of Darkness to Question them about the Prank. He learns that Cyrus recorded the music during the prank has become consumed by the hypnotic effects of the music becoming obsessed about it. Under the hypnotic effects of the music Cyrus quits the Dudes of Darkness. Biff, easily their biggest fan, is furious with Lee and promises retribution if he fails to reunite the band. Lee uses Barrages voice to snap Cyrus out of the trance in time for him and Lee to blow the crowd away at the battle of the Bands. Once home Lee contemplates listening to the Music to learn any information about the Prank, fearing that he might become consumed by it like Cyrus was.