"Change" is the name of the game for everyone in the 4th Season Opener as the Botwin family, homeless since their beloved town of Majestic has burned down, hits the road in search of a new place to call home and of course, grow Weed. Their leaving is right on time, as relentless DEA Capt. Roy Till continues to hunt for whomever is responsible for the temporary grow house, now abandoned by Conrad and Heylia. With all the real players gone, everyone fingers Celia as the culprit, but she points to Nancy; the family heads to Del Mar, where Andy's grandmother lives, but no...
Celia tries to adjust to life on the inside; Nancy runs into trouble making her first border run; Silas finds a new place to start growing; Roy Till begins to believe Celia's story; an argument between Andy and Lenny reveals more family history, while Bubbie finds a way to make a revelation of her own.
Nancy learns to traffic across the border, Bubbie wants to die, Shane talks to Grampa Lennie about it, Andy DOESN'T talk to his dad about it, Celia makes a deal to try to sell Nancy out, Doug gets confronted by the new City Council and there's an unplugging party.
Nancy, needing more cash, wants to get back into the selling game; Andy and Doug are determined to become "kinder and gentler" Coyotes; Lisa gives in to her attraction to Silas; Shane and Isabel stumble across some racy pictures that Judah took of Nancy when they were dating; Celia goes south of the border to buy her prescription drugs; Nancy gets very special treatment from Esteban after surprising him with a visit.
An impromptu lunch date for Nancy and Esteban ends in a hail of gunfire; Celia seems to have developed a dependency on Xanax; Silas tells Lisa what he grows, and Lisa offers him use of her shop as a cover; acting on advice from Cesar, Shane carries out a preemptive strike at his new school; Doug and Andy's Coyote business attracts some unwanted attention; as their dream date continues, Nancy learns more about Esteban's appetites and desires.
Nancy and Esteban have scheduling problems. Celia has become addicted. Nancy catches Silas and Lisa. Andy catches Shane masturbating with photos of Nancy. Cue Nancy giving the boys an uncomfortable lecture. Mexicans celebrate "El Andy".
Celia's family and friends arrange an intervention for her. Nancy gets a migraine from finding out that there is *another* use for the tunnel. Mexicans find Maria. Shane tries a threesome with Harmony and Simone. Silas pines after Lisa.
Nancy scares Harmony & Simone away. Maria wants Doug to win her heart before letting him have sex with her. It won't be easy. Celia has problems in rehab. The Tunnel keeps upsetting Nancy. Silas and Lisa's improved cheese shop is a success.
Nancy makes a risky deal with Capt. Till. Celia has a revelation. Maria comes on to Andy, even though Doug may have her deported. Nancy wants to hear Esteban say "it". Shane secretly keeps hanging with Harmony and Simone.
Esteban is unwilling to kill Nancy just on basis of Shlatter's word. Nancy denies knowing Guillermo's boss. Lisa's ex-husband catches her and Silas in the act. Celia goes to Mexico to see her estranged daughter. Doug opens Andy's eyes.