“Piece of cake.”
– Chuck

The “butterfly effect” is a metaphor that refers to the flapping of a butterfly’s wings causing small changes in the atmosphere that could prevent, delay, intensify, or redirect a tornado. It represents the idea that a small action can have wide-reaching consequences. Chuck’s trip to Paris in the previous episode seemed to be nicely resolved, but its aftershocks will be felt throughout the non-spy world.

If you haven’t already, make sure to read the disclaimer.

Devon has been a little jittery lately. His encounter with Sydney wasn’t exactly reassuring. Ellie, being a perceptive woman, notices this, and after seeing baggage claim tickets for a Paris trip on Chuck’s luggage, she senses that Devon is keeping a secret about Chuck from her. But Devon can’t spill the beans about Chuck’s spy life, so he must shoulder the burden of that scary secret himself. Chuck’s firm words do nothing to assuage Devon’s fears, which are only exacerbated after hearing Chuck lying to Ellie, telling her that he went to Paris on an installation job and kept it a secret because his good work earned him a free stay in the client’s flat, which he wanted to give to Ellie and Devon as a present. When Chuck’s gift of first class plane tickets arrives, Devon refuses to accept them, which causes a fight between him and Ellie, and he storms out of their apartment. Cracks are starting to appear in Devon and Ellie’s marriage, and a simple plane trip was the catalyst.

Meanwhile, at Buy More, Hannah is adjusting to her new job as a Nerd Herd employee. She is confused by Chuck constantly going off to the Orange Orange for frozen yogurt. When she asks Morgan, who has a crush on her, about it, she accidentally lets slip that Chuck went to Paris. Morgan tries to get Chuck to confess about the trip, but Chuck won’t. Morgan is devastated that his best friend is keeping secrets from him.

But all is not lost. Morgan and Ellie, the victims of the butterfly effect, have both noticed a change in Chuck. They want to get to the bottom of it and figure out why he and Devon are acting so weird. Damage has been done to the characters’ interpersonal relationships, but Morgan and Ellie are about to start the repair process.

Chuck and Sarah, however, are not partaking in this repair process. Though their relationship is amicable, they’re slowly breaking themselves. They’re victims of the butterfly effect’s irony. In this episode, Chuck has to befriend a fellow computer geek, Manoosh, and develop him as an asset. Manoosh is bizarro-Chuck; while he shares many interests with Chuck and is unlucky in love, his personality is totally different. He’s power-hungry, greedy, and selfish. He is building a powerful new weapon, and he doesn’t care who gets it in the end, as long as he walks away with a hefty wad of cash.

Chuck initially doesn’t see his new assignment as difficult. He even refers to it as a “piece of cake,” but he soon realizes that manipulating people and getting them to trust him is more challenging than it would appear. However, Chuck is a quick learner, and after a casual conversation at Two and a Half Amigos, Manoosh and Chuck have forged a “friendship.” But after Manoosh tries to sell his weapon to the highest bidder at Weapcon, Chuck must spring to action. For his own protection, Manoosh is headed for a deep, dark cell. At first, Chuck can’t bring himself to burn Manoosh, but much to Sarah’s horror, he does it the second time around, telling Manoosh, “I’m not [your friend]; I’m a spy.” Casey’s pronouncement that Manoosh is “no innocent” doesn’t assuage Chuck’s guilt. Chuck just gave a man a life sentence, and that man wasn’t even a true villain. It’s the same fate that would have befallen Chuck if he had attempted to use the Intersect in his head for selfish purposes. Without Sarah’s intervention, Chuck might have ended up where Manoosh is now. It’s all too much to take for Chuck, who turns to Johnny Walker for comfort when Casey and Sarah won’t provide it and Ellie, Devon, and Morgan can’t. What initially seemed like an easy “mish” turned into a humbling, emotional experience for Chuck, who must face what he was become all by himself.

“You were sweet and innocent. I liked you. That made it much harder.”
– Sarah

Sarah has been living out an experience similar to Chuck’s mission with Manoosh, but extended over two and a half years. Though with all the emotional fallout of Bryce’s betrayal and apparent death, recovering the Intersect wasn’t just another mission for Sarah, Chuck was just another asset: someone to be manipulated and later disposed of. At least, that was the case until Chuck helped out a ballerina and her father, took Sarah on a charming date to a Mexican restaurant, and then defused a bomb. Suddenly, Chuck wasn’t just an asset; Chuck was Chuck, a caring, genuine guy with a desire to do the right thing. Chuck became Sarah’s anchor to the real world. He provided stability, comfort, normalcy, and love, and didn’t ask for anything in return. But when Chuck decided to upload the Intersect 2.0 and become a real spy, he ripped that all away from her. Now Sarah is back to square one, but the additional pain of having lost what she truly wanted and of being the catalyst for Chuck’s decision. When she sees him coldheartedly burning Manoosh, she feels like Dr. Frankenstein, appalled by her own creation. It’s no wonder that she can’t bring herself to comfort Chuck and watches from video surveillance as he drowns his sorrows in alcohol.

And thus, the butterfly effect has affected Sarah as well. A regular, easy-to-manipulate asset ended up taking Sarah on a transformative journey, changing her perceptions of the world. Sarah never would have imagined that she’d spend more than couple of weeks in Burbank. She never would have considered that she’d find home. She never would thought that she’d fall in love. But all those things happened, for better or for worse, and Sarah can’t go back to how it was before. She’s a different person now. As if to emphasize that fact, the episode ends with a flashback to the pilot episode, but from her perspective. The flashback shows her receiving personal details about Chuck before meeting him at the Buy More, just like she would for any other potential asset. As she approaches the Nerd Herd desk, she utters three words that are laced with more irony than she could have fathomed:

“Piece of cake.”
– Sarah