No longer working for the government, Chuck enlists Morgan's help to search for his mother. Sarah and Casey must infiltrate a mysterious Russian company, and Ellie has important news to tell the family.
As the team tracks down a high-tech weapon in Milan during Fashion Week, Chuck discovers some issues in his relationship with Sarah. Morgan uncovers a flaw in Buy More's security, and Casey tries to acclimate himself to living in Burbank.
Chuck, Sarah, Casey, and Morgan must stop a scientist from releasing a nightmare-inducing toxin. Damaging information regarding Chuck's mother is discovered. Devon's mother pays a visit. Jeff and Lester deck out the Buy More for Halloween.
In order to repair his status as an agent and his relationship with Sarah, Chuck agrees to go on a dangerous mission with an eccentric partner. Morgan and Casey must stop Jeff and Lester from knowing the true identity of Greta at the store.
Things are turned upside-down the day after Thanksgiving when Chuck's mother drops by...along with as Alexei Volkoff. Morgan must deal with Jeff and Lester during the Black Friday sale at the Buy More.
Chuck, Sarah, and Casey must travel to Morocco to rescue suave former agent Roan Montgomery. Morgan meet's Alex's mother, and Mary Bartowski acclimates herself to civilian life and spends time with her new granddaughter.
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.
Chuck's leadership skills are tested when someone is found murdered in Castle. Ellie picks up a hobby that worries Awesome, and Morgan is stuck in the middle when the Buy Morons take on the neighboring Large Mart.
When the CIA targets Vivian Volkoff for assassination, Chuck turns to an unusual ally to protect her: Vivian's father, Alexei. Ellie suspects her mother doesn't want her to find out about her father's past.