Mammoth Mutt, Tail Terrier, and Paw Pooch compete for temporary leader when Brainy gets put to sleep by sleeping gas.
Veronica takes the stand in Aaron Echolls's murder trial, and is distracted during final exams while waiting for the verdict. Meanwhile, Keith takes new evidence about the mayor to Lamb, and Weevil asks Mac and Cassidy for help to pass algebra.
Jonas and his team must track down surface-to-air missles before they are smuggled out of Brazil after a deal with a drug lord falls through. Jonas gets help from a local boy who informs the team where the SAMs have been taken to be shipped. Meanwhile back on the base, Kim ends up causing even more trouble when she insists that the “Family Readiness Group” deals with what she deems more serious issues. Also, Williams tries to find a way to tell the woman he wants to marry that he is actually a Unit member and not a clerk on the base like she believes.
When a police officer with a gunshot wound to the head and uncontrollable laughter is admitted, House and the team are baffled. When Foreman begins showing the same symptoms, they race to determine the cause of the illness before Foreman's condition takes the same path.
Lorelai helps Emily while she's unable to see after minor eye surgery. Rory takes charge of Logan's recovery when he returns home.
The NCIS team must protect Ziva when a suspect dies while being in custody, and her tactic might be the reason why the person died. The things become much more dangerous when the suspect's brother kidnapps Jenny, and demands the release of his brother in exchange for Jenny, but he has no idea that his brother is dead.
When a proud and happy Ryan announces that Dana is pregnant, Jim warns him of Dana's upcoming hormone swings, and ends up dreaming that he is pregnant.
Moz is a drug dealer and has very strange clientele who come and go from his flat.
Name partner Edwin Poole returns from a mental institution to Crane, Poole and Schmidt, ready to jump back in, but Shirley has reservations when he decides to sue a candy company. An A.D.A. with a grudge against Alan brings charges, accusing him of advising his client to flee when a guilty verdict was inevitable. Meanwhile, Brad and Denise decide where to take their relationship.
Stabler teams up with an new partner to investigate a sexual attack on Jessica DeLay, a sixteen-year-old girl who worked tobacco stings for the Department of Health and face an overweight young brother and sister who claim it was an act of vengeance for Jessica and her friend, Tommy Strahan, beating up their older brother Rudi for being fat. Stabler and Blaine arrest DeLay and Strahan, but when the two are released due to lack of admissable evidence, Rudi Bixton takes justice into his own hands.
Ephram discovers that Bright cheated on Hannah and confronts him about it. Irv takes Edna along on his book tour, where they meet his daughter Cassie. Reid is faced with expulsion from medical school for cheating on an exam. Harold confesses to Andy that he neglected to report Rose's cancer on the adoption application. Ephram tells Amy what happened with Bright, prompting her to confront him and force him to admit the truth to Hannah.
A cruise ship that is docked in Miami is the scene for a double murder. The team investigates the long list of potential suspects but soon find that the list is dramatically decreased when the CSI's find a large amount of money is missing from the victim's stateroom. Horatio and Marisol's relationship evolves.
Breanna's Uncle Kevin flies in from Baltimore to try selling his line of hair-care products to L.A. salons; Breanna refuses to let Arnaz bring any of his dates into the house.
Joan cuts loose two of the men she's dating when she develops feelings for an NBA player. A traumatic event lands Toni behind bars.
Mona is taking her break-up with Chase out on everyone, only to realize that she's also putting her professional career in jeopardy. Dee Dee's newly signed client is married but when she suspects he's having an affair she is faced with a moral dilemma. Meanwhile, Phyllis and Big Dee Dee assume the girls are planning a big Mother's Day celebration, since neither has suggested plans to celebrate.
Vicki and Aaron Newton are separated, with joint custody of their two sons, Aaron (12) and Kobe (5). Though the boys are angels for Dad, young Kobe saves his worst behavior for Mom. He is violent and destructive -- hitting, kicking, slapping, punching and swearing. He even throws rocks at Jo's head. Aaron isn't physically aggressive, but he does talk back to his mother. For the first time, Jo Frost observes life in two homes to hone her recommendations for each parent. But can she get them to collaborate on their child-rearing techniques?
When a serial dog killer starts stalking local parks, the team are reluctantly forced into taking on the case.
Doug and Deacon discover they have more in common with each other's wives than their own, so they start hanging out with each other's wives as well. When Kelly tires of Doug, he ruins Deacon and Carrie's good time. Meanwhile, Arthur dispenses romance advise, and the recipient finds success simply doing the opposite.