Chuck and Morgan search the globe for Chuck's mother (Linda Hamilton); Casey and Sarah track an operative (Dolph Lundgren) of the mysterious Volkoff Industries; Ellie shares big news.

When Chuck (Zachary Levi) and Sarah (Yvonne Strahovski) go undercover in Milan, Chuck realizes the "Achilles' Heel" in their relationship, but must set personal issues aside for the mission. Meanwhile, Morgan (Joshua Gomez) recognizes a fatal flaw that compromises the new Buy More. Elsewhere, Casey struggles to put down roots in Burbank

Chuck and Sarah's romantic mission is cancelled with the arrival of Hugo Panzer and Heather Chandler. But Chuck grows more interested when the manipulative Heather claims to know a secret about his mom. Meanwhile, as Morgan prepares the Buy More for a huge video game release, he gets a surprise from Big Mike.

Chuck and Sarah work on becoming better communicators as they join Awesome and Ellie for a getaway to Costa Gravas. There, the gang is reunited with Generalissimo Goya who finds himself in a dangerous situation once again. Back at home, Morgan embarks on a forbidden romance that may put him at odds with Colonel John Casey.

When Colonel Casey's former team returns looking for him, Chuck must decide what he's willing to sacrifice in order to find his mom. Elsewhere, Morgan works up the nerve to reveal a potentially dangerous secret to Casey.

When Chuck, Sarah, Casey, and Morgan are tasked to stop Dr. Stanley Wheelright from releasing a nightmare-inducing toxin, they're also lead to question the allegiances of Chuck's mom. Meanwhile, Jeff and Lester use their unique sensibilities to celebrate Halloween at the Buy More, and Ellie and Awesome get a visit from Dr. Honey Woodcomb.

After their first real fight, Chuck avoids confronting Sarah by going on a rogue mission that leads him to his mom's MI-6 handler, Gregory Tuttle, and a mysterious Russian agent. Meanwhile, Ellie is on her own mission to uncover the Bartowski family's long-buried past.

Afraid that his latest setback is driving a wedge between him and Sarah, Chuck resolves to prove himself by going on a dangerous mission with the overeager Agent Rye. Meanwhile, Morgan and Casey scramble as the "Buy Morons" attempt to uncover the true identity of Greta.

Chuck, Sarah, Casey and Morgan venture into the jungles of Southeast Asia when The Belgian attempts to unravel the secrets of the Intersect. Meanwhile, Captain Awesome and Ellie try to decipher a secret left behind by her father.

It's the day after Thanksgiving and Chuck faces the most awkward of family reunions when mom comes over for dinner - along with the dangerous Alexei Volkoff. Back at the Buy More, Morgan deals with the busiest shopping day of the year as Jeff and Lester hatch their latest scheme.

When an assignment brings him to a French vineyard, Chuck juggles tracking down a nano-chip with trying to create the perfect romantic getaway for Sarah. Back at the Buy More, Lester comes to Big Mike for his own romantic problems.

Sarah takes dangerous measures to help Mary Bartowski bring down Alexei Volkoff, as Chuck worries that she may be getting in too deep. Sarah, though, must enlist the help of Chuck, Morgan and Casey to complete her undercover mission. Meanwhile, Ellie and Awesome are at odds over what to name the baby.

As Sarah works to free Chuck's mom, Chuck and Morgan embark on their own mission to take down Alexei Volkoff. Meanwhile, Casey bonds with his daughter, Alex, while Ellie tries to ease Awesome's anxieties over fatherhood.

In need of an exciting new mission, Chuck, Sarah and Casey are sent to Morocco to rescue Roan Montgomery. Meanwhile, Chuck and Sarah are at odds over their future plans. Back at home, Morgan prepares to meet Alex's mom, as Mary bonds with her family.

Chuck surprises Sarah with her old spy team, The C.A.T. Squad, leading to a mission in Rio. As The C.A.T. Squad works to settle a score with Augusto Gaez, old secrets and grudges come to light. Back at the Buy More, Morgan fends off the advances of Carina, a former flame and frisky member of The C.A.T Squad.

Valentine's Day is interrupted when Chuck and the team are sent on a mission to England to protect a reclusive young heiress, Vivian McArthur. Meanwhile, Casey gets an offer from the mysterious Jane Bentley. Back at home, Ellie and Awesome find an unlikely solution to a parenting problem, as Morgan ponders a big move.

Chuck pushes Vivian McArthur to get in touch with her inner villain for a mission. Elsewhere, Sarah tries to get in touch with her inner bride as wedding plans ramp up. Meanwhile, Morgan's search for a new roommate takes an unexpected turn.

Chuck and Sarah suspect Casey is carrying out private missions; Chuck fears the CIA's new operatives will render him obsolete; Morgan settles in with a new roommate; Awesome becomes uncomfortable with Ellie's research.

Chuck is put in charge of a top-priority mission, but his leadership skills are pushed to the limit when there is a murder in Castle. Meanwhile, Awesome takes on a mission of his own when Ellie finds an alarming new hobby. Elsewhere, Morgan's leadership is also tested when his Buy More troops wage war against Large Mart.

A bad day gets worse when Sarah throws Chuck a surprising relationship curveball as the CIA orders Vivian Volkoff assassinated. In order to prove Vivian's innocence, Chuck must put his trust in a dangerous ally her father Alexei Volkoff. Meanwhile, Ellie suspects that her mother is interfering with the search into her father's past.

In this Section we discovered that Chuck and Sarah determined to take help from Sarah's conman dad, Jack Burton as they think they have been mislead out for their marriage cash. Meanwhile we observe that Morgan is trying to pressurize Casey to have a concept with Alex's mom. Will Casey be able to discuss to Ales's mother?

In this episode Chuck and Sarah decided to spent their weekend in debauchery, but all the wonderful plans do move as planned. Both of them has decided to take a short leap from spy work. In the mean time we see that Ellie discovers a secret while investigating her fathers computer. What impact will this life Changing discovery lead her to?

Chuck and Sarah's wedding prep includes one final detail: ensuring that the mother-of-the-groom makes it to the ceremony alive. Meanwhile, Morgan's responsibilities as Best Man include his most dangerous mission yet, as he faces Vivian Volkoff. Elsewhere, Ellie tends to the last details of the rehearsal dinner and seeks help from an unlikely source.

Before he can kiss the bride, Chuck must enlist his wedding party to take down Vivian Volkoff and stop her from destroying the big day. When he turns to Alexei Volkoff for help, the CIA sends its toughest agent, Clyde Decker, to stop them.