Penny's home business turns into a complete nightmare when Sheldon takes over.
Peyton and Lucas deal with shocking news about Peyton's pregnancy as Brooke and Julian face a crossroads in their relationship. Meanwhile, Nathan and Haley celebrate their anniversary, with Dan and Deb babysitting Jamie; and Mouth and Millie work to redefine their relationship.
The team blows Bobby's cover when they investigate a murder; Grace has suspicions about Abby; Rhetta and Johnny meet with Leon.
Xero, the evil boy computer genius, takes over a high-tech skyscraper and challenges Aaron to fight his way out through a gauntlet of modern office equipment that has turned deadly.
After discovering Latnok's true purpose, Kyle enlists everyone to stop it at all costs, but keeping all his cover lies intact and protecting Jessi may endanger the operation.
When a flight attendant is murdered, the CSIs uncover all the dirty secrets of airplane travel.
A convicted murderer who has been studying law inside is given the chance to appeal and chooses to represent himself in court against James Steel - his former prosecutor.
Jealous of Hank's new toy robot, Davis places an order online but is surprised when his robot arrives. Despite Emma’s warning, Lacey's quest to expand Brent's culinary horizons and turn Brent into a food critic from hell. Wanda suits up to help Oscar combat a beehive.
Hannah pretends to date a celebrity she can't stand to get in the news. Jackson thinks that he has to cheat on a test in school. Robby clashes with Rico.
Unable to communicate with the outside world, the Unit and their families must survive when a deadly gas poisons anyone in their community who steps outside.
Susan tries to impress a teacher at work, Gaby talks Carlos into hiring Lynette, Edie continues to look into Dave's past.
Walt and Jesse find themselves in close quarters with an unhinged Tuco. Marie and Hank comfort Skyler, who is distraught over Walt’s disappearance. Hank pays a visit to Mrs. Pinkman on some not-so-official business.
Kenny decides to give up on his dream of returning to professional baseball. Meanwhile, arrogant car dealer Ashley comes back into the picture.
Longtime friend and pro FMX rider, Ronnie Renner, invites the Nitro crew to his California ranch, where newfound friend and show producer, Johnny Knoxville, is waiting to play a little bull croquet. In between all the madness, the cast find time to drop in on their friend, Rob Dyrdek, at his fantasy factory. After the factory, the cast get back to what they do best: a spectacular chaos crossover involving five motorcycles, a cab, a mountain bike, and a high-powered trophy truck.
Jemaine and Dave help Bret woo the clerk at the cheap zoo (pet shop). Jemaine also helps Murry seek forgiveness from Greg.
Lisa infiltrates a convent in order to steal back Maggie who was accidentally taken in by nuns. While in the convent, Lisa uncovers a series of cryptic clues leading to a hidden jewel in Springfield. With help from resident history buffs Principal Skinner and Comic Book Guy, Lisa sets off to find the coveted prize. But Springfield's Freemasons are also hot on the trail of the jewel, and Lisa must race against them to find the jewel and rescue Maggie.
Steve connects with his ne'er-do-well paternal grandfather, whom Stan despises for many reasons, not the least of which is that he never taught him to ride a bike. Meanwhile, Hayley must find an internship quickly, so Roger hires her to tend his bar.
Dorcas welcomes a hospitalised James' son into the post office, causing turmoil.
Amy heads into the mountains to visit a First Nations horse healer named Victor Whitetail, and leaves with a new understanding about horses, her mom and herself.
Nicki's homecoming, after a visit from her sister wives, isn't what she imagined; Barb endures a trying experience at her old church; Ted does an about-face on the casino project; Scott's reunion with Sarah doesn't go over well with her father or brother; Joey is upset by Bill's change of heart about Roman after the Greenes' latest move.