Jake shares that he has heard his mother having sex with her fiancée, Herb; this revelation brings up a repressed memory for Charlie. This leads Charlie to seek help from Rose.
As PCP spreads through Cassie's high school, Val, a new undercover cop, Eddie and Lund are assigned to find and take down the dealers, but when Charles sees Cassie flirting with Val he isn't happy about it – and neither is Eddie. Elsewhere, Lizzie is thrown into a predicament: does she break a promise to protect her friend from embarrassment or should she betray another friend's secret, and possibly ruin her first slumber party.
Supernanny Jo Frost travels to Hawaii to help Will and Michelle Smith -- they are highly intelligent marine biologists, but when it comes to bringing up their two boys, they're clueless. Three-year-old Nate is still in diapers, and 18-month-old Ari screams at the top of his lungs to get his bottle. Bedtime is a nightmare, as Dad hypes the boys up with a frog-hunting outing right before they're supposed to be going to bed, leaving both parents exhausted and up for hours with the two energetic boys. Will and Michelle foster a house full of high energy and crazy fun, but all their singing and dancing (including the "pee-pee dance") can't tame the kids -- they freely admit the children are totally in charge. The parents have read the books, talked to experts and still can't figure out a way to control their toddlers. Without mastering even the basics of discipline, they worry that, if they can't cope with their children now, they'll never cope with their boisterous boys in the future.
Brent neglects to get Emma a present for Mother's Day, causing her to see red. To make matters worse, Hank shows up with a present, creating a rivalry in Emma's mind. Oscar takes full advantage of the situation when he realizes that he can get away with anything, due to Emma's distraction. Lacey and Davis try to out-embarrass each other, while Karen and Wanda have some trouble putting together their purchase from a Swedish Superstore.
A young school girl is raped and murdered, but D.C.I. Connor still has no leads a month into the investigation. When Walker orders a review of unsolved cases, they turn up similar cases of raped and murdered teenage girls over the last ten years, and they find themselves searching for an apparent serial killer.
After Kris Furillo's trailer burns down, her sense of independence is tested when she has to move in with the Ritter family.
After Frank steps on a land mine at a crime scene Horatio and the Bomb Technicians must deactivate the bomb. Delko gets hit with a large lawsuit after breaking up a domestic dispute.
As tension builds between Grace and Boyd the truth about Lisa is revealed. Meanwhile, the team have a new lead following on from Declan's death and it's a race to find the murderer before Lisa does.
Lynn is crushed by discouraging news and considers leaving Los Angeles. Darnell constantly feels humiliated by the new owner at his old job.
Four more "suitcase nukes" are out there, and Jack's only lead takes him to the home of his brother.
For a lesson on parenting skills Chris is given an egg to take care of as if it were his child. When the electricity bill is over budget, Julius decides to figure out why. Drew a werewolf? That's what Tanya thinks so she's afraid to sleep.
When Ted is constantly insulted by his former boss, who is now working for him on a project, he is told to fire the man, but he finds that a hard thing to do. Meanwhile, Barney offers Lily a lot of money to paint a nude portrait of him.
Bellick gets a taste of the medicine he gave out when he was the Captain and Agent Mahone's ex-wife makes another appearance.
Matt reveals his abilities to his wife. HRG confers with Mohinder. Now that she knows the truth, Claire tries to make sense of her life. Hiro seeks the sword that he is destined to own. Niki must face the consequences of her decision to turn herself in to the police. Simone and Nathan are worried about Peter, who has been in a coma for two weeks. Peter meets a new hero. Micah visits his mother.
Gabrielle cannot avoid Zach. Mike's new lawyer suggests he pleads guilty, but Susan doesn't agree with that. Gloria informs Bree that she and Alma believe Bree is the other woman. Instead of going back to work Lynette pretends to be ill so she can help Tom promote the pizzeria at a food fair.
A young boy wants to hire Harry because he believes that monsters are after him and his mom. Harry doesn't want to take the kid's money, but he also knows from his own experience that a child's monsters are often all too real.
Lu and Jordan are working together on the suicide of a teen. A note left by the teen suggests that he had been molested. A woman has been hit by several cars on a freeway, Woody is investigating. Later an investigator pops in and starts digging around. Dr. Macy offers Jordan a word of advice; Lily gets some surprising news.
The family throws a party for Nora's sixtieth birthday. Surprises- but not the good kind- abound when half the family gets the flu, Nora's mother shows up, and the video tribute doesn't come out quite right.