Meanwhile, Casey and Morgan try to protect Jeff and Lester from the truth when they snoop around to find out the true identity of Greta ( Summer Glau). Worried his relationship with Sarah is souring, Chuck aims to impress by attempting a dangerous mission with the help of Agent Jim Rye ( Rob Riggle) to retrieve a diamond being sold by Adelbert de Smet a.k.a. Meanwhile, Ellie digs into her family's secretive past. In their attempt to prove Mary Bartowski's innocence, they are attacked by Dasha ( Ana Gasteyer), a nefarious Volkoff operative. Meanwhile, the true allegiances of Mary Bartowski come under scrutiny, and the Buy More gang celebrates Halloween.Д¬huck embarks on a rogue mission with Gregory Tuttle ( Timothy Dalton), his mother's handler at MI-6. Stanley Wheelwright ( Robert Englund) who is plotting to sell a toxin that induces nightmares. Team Bartowski battles sinister scientist Dr. Elsewhere, Morgan works up the nerve to reveal a potentially dangerous secret to Casey. When Casey's Clinton-era team ( Dave Bautista, Eric Roberts and Joel David Moore) returns looking for him, Chuck must decide what he's willing to sacrifice in order to find his mother. Back at home, Morgan embarks on a forbidden romance that may put him at odds with Colonel John Casey. However, Goya's wife ( Tia Texada) has other plans. Chuck and Sarah work on becoming better communicators as they join Devon and Ellie for a getaway to Costa Gravas. Indebted to Devon for saving his life in ' Chuck Versus the Angel de la Muerte', Premier Alejandro Goya ( Armand Assante) shows his gratitude by inviting the gang to his beautiful island. Meanwhile, as Morgan prepares the Buy More for a huge video game release, he gets a surprise from Big Mike. But Chuck grows more interested when the manipulative Heather claims to know a secret about Frost. Also guest starring Lou Ferrigno, Karolina Kurkova as Sofia Stepanova, Isaiah Mustafa as Greta, and Bronson Pinchot.ДЄ prison transfer delivers old foes, Heather Chandler and Hugo Panzer ( Nicole Richie and 'Stone Cold' Steve Austin), to Castle, canceling Chuck and SarahвЂ™s romantic mission. Meanwhile, Morgan discovers a vulnerability about the new Buy More. There are crimes of fashion when Chuck and Sarah go undercover in Milan for Fashion Week to seize a high-tech weapon, yet Chuck soon recognizes a flaw in his relationship with Sarah. Olivia Munn appears as the inaugural Greta, a rotating character. Back at home, Ellie delivers big news to her family. Sarah and Casey follow a trail to Russia as they investigate the mysterious Volkoff Industries and its operative, Marco ( Dolph Lundgren). When the CIA gains control over the Buy More, Chuck begins searching for his mother ( Linda Hamilton). Mini Anden as Carina Miller (2 episodes).Richard Chamberlain as The Belgian (2 episodes).Robin Givens as Jane Bentley (3 episodes).Lauren Cohan as Vivian McArthur (5 episodes).Olivia Munn, Isaiah Mustafa, Stacy Keibler, and Summer Glau as ' Greta' (5 episodes).Timothy Dalton as Alexei Volkoff (6 episodes).Linda Hamilton as Mary Elizabeth Bartowski (11 episodes).Mekenna Melvin as Alex McHugh (12 episodes).Bonita Friedericy as Diane Beckman (21 episodes).Vik Sahay as Lester Patel (18 episodes).Scott Krinsky as Jeffrey Barnes (18 episodes).Mark Christopher Lawrence as Michael 'Big Mike' Tucker (16 episodes).Joshua Gomez as Morgan Grimes (24 episodes).Adam Baldwin as Colonel John Casey (24 episodes).Yvonne Strahovski as Agent Sarah Walker (24 episodes).Zachary Levi as Agent Chuck Bartowski (24 episodes).See also: List of Chuck cast members Main cast

Chuck season 4 episodes for