Plot

Chuck and Sarah's Valentine's Day is put on hold when they must travel to England to protect an oil baron's daughter. A mysterious woman makes Casey a compelling offer. Ellie and Devon receive parenting help from an unusual source.

SAMARA, RUSSIA

A man tries to start his car. Someone gets in and asks for a key that Volkoff supposedly gave him. But Jurek (who got promoted from his job as Peggy from USA Prime Credit) claims the key is with Antonia. Right answer, same result: a bullet to the back of the head.

PERUGIA, ITALY

Antonia is found, and the man has an intense makeout session with her. He still wants the key but she also claims not to have it. But she knew about Jurek, so she was armed with a gun. Only the man had her bullets. His gun, however, was working just fine.

BREMEN, GERMANY

A man, Christoph, prepares dinner, one of Volkoff's last lieutenants. Once again, the man wants his key. He doesn't have it, but he knows who does.

ECHO PARK, CALIFORNIA

Chuck (Zachary Levi) and Morgan (Joshua Gomez) prepare the apartment for their Valentine's dates with their girlfriends, marking a first in history both of them having girlfriends. They agree to timeshare: Morgan gets the living room from 8 to 9:30, at which point Chuck gets it to watch with Sarah (Yvonne Strahovski). (Really, Chuck?) But Morgan can top him with a bear-skinned rug. From Big Lots. (He bought 8 of them.) While Ellie (Sarah Lancaster) and Awesome (Ryan McPartlin) try to have sex for the first time in three months by trying to ignore Clara's crying (and failing at it), Sarah prepares for Chuck...and the 70's music in the background...and his Love Machine t-shirt with his face on it...which will be half the fans' profile avatars by morning. He even threw a at her. ("Isn't that a movie about a prostitute?") And Sarah wearing a trenchcoat in the bedroom is never a bad thing, unless Chuck has to go get the chocolate strawberries from the refrigerator and catch Morgan and Alex (Mekenna Melvin) blindfolded playing the "forcefield" game...or something tantric-related. (If you need it explained, I refuse to do it; you'll just be depressed.) Chuck accidentally drops the strawberries, only to be caught by Sarah, who gets her coat caught on a hook, and Beckman interrupts with a phone call, Morgan coats Alex with chocolate sauce, Sarah's lingerie with angel's wings goes wasted (that was CUTE!!!), and Casey's (Adam Baldwin) arrival because they have a mission pretty much ruins the night for everybody.

MORGAN: Chuck, you said I have the living room for ninety minutes!

CASEY: (threatening) What do you mean 'HAVE'?

As the NCS sets up shop in Castle, Beckman (Bonita Friedericy) informs the team (who didn't bother changing clothes), that Volkoff's three top lieutenants were killed by one man: Boris Kaminsky (). Beckman theorized Kaminsky was trying to eliminate anybody who could fill the void in Volkoff's empire. The only profile not available in the Hydra database was a woman named Vivian McArthur (Lauren Cohan). Volkoff kept her off the books on purpose to be his successor. The team has to head to England to find her at a masquerade party and bring her back to Castle.

If you're thinking the masquerade party looks a bit like , Chuck agrees with you. Only it's less boring.

SARAH: Chuck, come on. It's just a bunch of socialites wearing masks.

CHUCK: It could be that, or it could be a sex-crazed orgy party where they don't want you to see their faces or know their secrets.

SARAH: (matter-of-factly) No, I've been to those kinds of parties and it doesn't look anything like this.

(she was kidding...dammit)

Casey and Morgan pulled bartender detail, although Casey got compliments from a woman about his skills. And from Morgan, too. Casey claims to still be an integral part of the team, and Morgan shouldn't talk about being a wet blanket.

CASEY: You live in Charah's apartment.

NOOO!!!!!! CASEY IS A 'SHIPPER!!!!!!! HUMAN SACRIFICE! DOGS AND CATS LIVING TOGETHER!! MASS HYSTERIA!!! :-D

Casey warns Morgan he might want to find his own place rather than be Chuck and Sarah's first kid. Chuck manages to find Vivian in his own special way...by stealing her wine glass after eating a too-hot hors d'oveurs. Although she agrees with him on the whole thing. Meanwhile, Sarah found Kaminsky by spotting the gun under his coat. Vivian slips past Chuck, but everybody is on the alert.

Vivian gets some peace and quiet in the horse stable, but Chuck and Sarah locate her and identify themselves. She is ready to run from them until a shot from Kaminsky's men convinces her otherwise. Vivian has the mansion in Somerset because of her father, Alexei Volkoff. However, she thinks he's an oil baron. But explanations later, as Chuck and Sarah take Vivian to a nearby car and drive out with Sarah shooting anything that moved out of the sunroof. They retrieve Morgan and Casey and take off.

Ellie and Devon head to the Buy More looking like death warmed over...and smelling like vomit and Cheerios, according to Big Mike (Mark Christopher Lawrence). (Every parent in the world is nodding their heads right now.) Amazingly, the Buy More has an aisle for this, and Big Mike introduces them to the Sleep Sheep, which can play a recording of Mommy's soothing voice. But apparently Jeff (Scott Krinsky) uses it, too...with a song that puts Clara right out! Ellie and Devon think about asking to borrow it, but sleep-deprived Ellie has a better plan. From the "should have seen that coming a mile away" department...Ellie pretends she's looking for a quiet place to breastfeed Clara. Moths, meet flame. Jeff and Lester (Vik Sahay) follow her, and the Sleep Sheep is Devon's!

In Castle, Vivian's story seems to check out, but it doesn't resolve the issue of her having a key Kaminsky would want. And they have a bigger problem: Morgan took what Casey said to heart about crowding Charah too much. (Hey, if Casey can say it, so can I!) Sarah decides she'll talk to Morgan while Chuck continues to debrief Vivian. She figures it would be good for Morgan and her to have some quality (read: AWKWARD) one-on-one time. Give Sarah an A for effort, but you don't want to refer to action figures as toys. And NEVER imitate Chewbacca! Although now Sarah knows Chewie always goes on Han's right side. But suddenly Morgan realizes Casey was 100% correct, and he has to stop being a big kid with Chuck and Sarah his parents.

Chuck isn't having much more luck with Vivian, who can't wrap her head around the fact her father killed people for a living. Suddenly Vivian was at a crossroads, because she was never a good socialite anyway. She didn't know what she was supposed to do. But Chuck talked about what happened to him a few years ago. An "opportunity" fell into his lap. Just like an opportunity that was about to fall into Casey's lap, courtesy of Jane Bentley (Robin Givens), head of the NCS. She saw his true potential, and it wasn't as third wheel bartender to Chuck and Sarah. Bentley wants him to lead a new team, but she didn't give him any details. Casey's interest was piqued. Speaking of piqued interest, Vivian didn't want to go to a CIA safehouse. She wanted to be used as bait to draw out Kaminsky. Chuck doesn't want to do it, but Vivian wants to be able to do something for the first time in her life. Chuck agrees.

Back at Ellie and Devon's, the song works great for Clara. For Ellie and Devon, not so much. Naturally, Clara cries the minute the song stops, so the Drs. Woodcomb decided to tough it out like it was their internship days. Chuck tries to stop Morgan from moving out, but Morgan reminds him Chuck will be married in a few months and he should have his own place with Sarah. All they really have to do is rule on who gets the original '77 Kenner line Star Wars Han and Chewie. You can never split them up. But they'll spend one night apart. Han and Chewie high-five, and Chuck is a bit depressed. Maybe shouldn't have been depressed in front of Sarah, but she is sorry about Morgan.

Vivian discusses the details of her typical day, since the team had to figure out at what point she'd be most vulnerable. It turns out, she takes her horse, Artemis, out for a ride at six every morning. This particular morning, however, it would be Sarah taking Vivian's horse out for a ride. Casey hides in the woods with his sniper rifle. Sure enough, Kaminsky was ready to attack. Only he attacks nowhere near Casey by using an electronic device to spook the horse. The horse throws Sarah and she's knocked unconscious. The horse returns to the stable without Sarah. Chuck calls for Sarah but she doesn't respond. Vivian isn't going to let anybody die for her, so she mounts up and heads out with Chuck.

It doesn't take long for Kaminsky's men to discover it's Sarah. He orders her killed, but Casey shoots the man before he can kill Sarah. Sarah is woozy and tells Casey to go get Chuck, but he refuses to leave her there. Chuck and Vivian are chased by men on horseback, and ten years of equestrian school finally pays off for her. Chuck figures out Artemis can't outrun the bad guys with two people on him, so Chuck flashes on some good gymnastics and uses a conveniently-placed branch like a parallel bar. Two bad guys down later, he tries to find Sarah and Casey. Casey digs in and puts his sharpshooting skills to good use, taking out all of Kaminsky's men. Vivian makes it back to the stables, but so does Kaminsky. Volkoff apparently gave Vivian a key when she was a child, a token of his affection. Vivian thinks he's out of his mind, but Volkoff was grooming her to be his successor. Skeet shooting at seven, a black belt by age eleven, and fluent in five languages courtesy of the London School of Economics.

KAMINSKY: But he never discovered what you really are. A weak, indecisive little girl...

...who pats Artemis to jump into the air so she can get the shotgun hidden under his harness and blow a hole in Kaminsky.

Without anybody to run Volkoff's empire, it was just an empty office building in Moscow. But they never did figure out what the key was. Although Vivian was very careful to take back the necklace she let Sarah borrow to imitate her.

Back home, Chuck tells Morgan how much Sarah and he love him, but Morgan realizes it has to end at some point. But there's still Monday game nights. And Han and Chewie get passed down to the next generation of Bartowski. They are keeping watch over Clara, who is finally in the nursery.

Bentley commends Casey for his work with Chuck and Sarah, and obviously he still was of great use to the team in saving Sarah's life. But Bentley tells him he'll eventually have to leave the team. Casey refuses to leave Burbank, but Bentley's mission is right there in Burbank. A secret door with a brick wall. What is it? And more importantly, what will Vivian do with Volkoff's empire? Where she found a message to her that only her necklace could unlock? What did she find? Tune in next time!