Gordo skips a grade and gets promoted to high school. After initial euphoria, Lizzie and Miranda start to miss Gordo.

Lizzie tries out for cheerleader but doesn't do very well. Later that night she and Miranda chat online. Lizzie jokes that Kate made the squad because she stuffs her bra. Miranda accidentally sends out the message to everyone on the class roster. The next day at school Kate is furious about the taunting she's receiving and confronts Lizzie and Miranda, demanding to know who is responsible. Lizzie stutters and stammers for a few moments, then Miranda says that she did it. Kate promises to make her life miserable, and a war of dirty tricks breaks out between the two. Miranda tells Lizzie that she took the blame because Lizzie can't handle conflict. Lizzie feels guilty as the war between Miranda and Kate escalates. Finally Lizzie works up the nerve to take responsibilty for the message and she stands up to Kate. Also, Matt brings home a lizard for a school project and names it Lizzie, much to his sister's annoyance. While Mr. and Mrs. McGuire are supposed to be watching the lizard, it die

Lizzie, Miranda and Gordo all have big problems on the day their pictures are to be taken for the junior high yearbook. Lizzie searches and searches for the right thing to wear, but her mother insists she put on a ""hideous"" sweater that her grandmother gave her. Miranda runs afoul of Kate when they both show up wearing the same outfit. And Gordo feels the pressure to assume a tough-guy pose when his picture is snapped. Meanwhile Matt hasn't studied for a quiz at school, so he fakes being sick to get out of it. But he finds out that his mom's cure can be worse than the disease.

Lizzie is looking forward to the science class field trip, but she is mortified when she finds out that her mother is a last-minute replacement as the girls' chaperone. Lizzie fears that her mother will embarrass her to death, and Mom does a pretty good job of doing just that while they are competing with the boys on a nature walk. But Mrs. McGuire proves how cool she can be when she helps the girls get back at the boys for a prank they pulled then takes all the blame herself. Back at home, Matt and Mr. McGuire are left on their own and try to cook for themselves.

Lizzie and Miranda are ecstatic about being invited to a pool party given by their heartthrob, Danny Kessler. Mrs. McGuire is excited for Lizzie too until she finds out it's on the same day as grandma's 80th birthday party. She tells Lizzie she has to go to her grandma's instead and Lizzie is furious. The next day at school Miranda temporarily gets on the good side of Kate, the girls' former best friend who has literally and figuratively outgrown them. Kate invites Miranda to hang out with her crowd, causing a conflict between Miranda and Lizzie. At home Lizzie catches her mom on the phone making up a lie to get out of a commitment and accuses her of being a hypocrite. Gordo helps Lizzie to smooth over her differences with Miranda. Mom tells Lizzie she can go to the party after all, but she decides not to and spends the day with Gordo.

Lizzie is dissatisfied with being an ordinary ""B"" student and is looking for something at which she can excel. Surprisingly, she finds out in gym class that she has a real talent for rhythmic gymnastics. But she thinks the sport is stupid and is ambivalent about competing. She trains hard and goes to the regional competition, where a jealous Kate tries to sabotage her performance. Miranda and Gordo help foil Kate's plan and Lizzie wins first place. Her parents are proud but Lizzie decides to give up the sport and go back to being her ""ordinary"" self.

Gordo is sure that Mr. Pettus is giving him ""B""s instead of ""A""s because Pettus doesn't like him. His state of mind isn't helped any when the teacher gives the class an aptitude test which shows that Gordo is best suited to be a blackjack dealer. To prove that Mr. Pettus has it in for him, Gordo convinces Lizzie to turn in his science project with her name on it and vice versa, which ends up having disasterous results. Also, Matt adopts a hip-hop attitude and insists that everyone call him ""M-Dogg.""

Lizzie and Miranda are excited about the news that singer Aaron Carter is coming to their town to do a video shoot. They enlist Gordo to help them figure out where the shoot will take place so they can crash the set and meet Aaron. Matt horns his way into the group also. When they arrive at the site Matt is mistaken for Aaron's stand-in and let on the set, but the other three are not. They try several ways to sneak in but are always chased off by a security guard. In all the confusion Mr. and Mrs. McGuire somehow manage to get detained by security. Aaron's manager catches the trio and Lizzie convinces her to at least let one of them meet Aaron. She agrees, and Lizzie tells Miranda that she can be the one. Lizzie goes back to get a tape recorder she left behind and runs in to Aaron, who gives her a kiss. The kids all get to be extras in the video.

When a babysitter cancels on the McGuires, Lizzie suggests that she's old enough to do the job for her brother Matt, but mom and dad say no. After much persuasion from Lizzie they relent, and Miranda and Gordo also come over to help. After Mr. and Mrs. McGuire leave, Matt generally causes havoc, spilling grape juice on the rug, acting bratty and taking advantage of Lizzie, who badly wants to impress her parents with her responsibility. Miranda and Gordo aren't much help as they won't follow Lizzie's orders either. At the restaurant Sam McGuire wants to sneak home and check on his daughter and son; Jo doesn't like the idea, but says just don't let them see you. Meanwhile at the house, Matt has knocked out the power. Mr. McGuire tries to peer in the window and goes tumbling over. The kids think he's a burglar and call the police. Mr. McGuire tries to get in the locked house and the kids wage a battle against him reminiscent of the movie Home Alone. The police come to arrest Sam. After al

Lizzie and friends are frustrated--the only candidates for school president are super-popular cheerleader Claire Miller and oddball Larry Tudgeman, who promises to eat a worm for every vote he gets. Gordo encourages Lizzie to run as a ""normal"" candidate and Miranda seconds the motion. Lizzie agrees to do it. Gordo is her gung-ho campaign manager as she runs on a ""voice of the people"" platform. Lizzie starts to gain confidence, even enough to tell off Claire and Kate. Gordo thinks she should schmooze the ""second-tier"" popular kids in the drama club, so Lizzie puts on her shades and black leather and tries to get in good with them. Miranda is annoyed that Lizzie is blowing off the less popular kids and groups to hang with the drama club. Lizzie starts to develop a prima donna attitude and now Gordo has to agree that he has helped create a monster in candidate Lizzie.

Mrs. Stebel pairs up the students in her social studies class for a mock marriage assignment. Each set of partners must draw a job from a jar at random, work up a fictional lifestyle and report back at a pretend 20-year reunion. Always-snobby Kate is horrified to find herself matched up with Larry Tudgeman, but at least she likes her job, a television anchorwoman. Lizzie wants to be partnered with Ethan Craft, who's not so smart but is cute. But she gets familiar old Gordo, whose job is sanitation engineer (garbageman). Lizzie figures it's not so bad, though, since Gordo will probably ensure she gets a good grade. Her mind begins to change when Miranda gets picked to be Ethan's partner, and he's a surgeon to boot. Lizzie can't help but be jealous.

Lizzie falls in with a bad crowd when she befriends "bad girl," Angel, at school.

Lizzie and Miranda note that when a girl gets her first bra, her personality somehow seems to change. They decide they are ready for their first, and hatch a plan to get Lizzie's mom to take them to the mall where they will shop for ""school supplies."" Lizzie is a terrible liar, though, and blurts out the real reason for the trip. Mom is overjoyed to help the girls out, but she embarrasses them as they are shopping. Lizzie is very harsh with her mother, telling her that she and Miranda are old enough to do their own shopping and to leave them alone. The girls face further embarrassment when they run into Kate, Claire, and their English teacher Mr. Coppersmith. They also find that they don't know what to look for.

Gordo, always the nonconformist, has a new passion: 1950s & '60s Las Vegas lounge culture, as epitomized by Frank Sinatra and the ""Rat Pack."" Lizzie and Miranda don't care for it, but they buy Gordo a Rat Pack CD. Ethan Craft listens to it on the bus and, surprisingly, likes it, which makes the girls reconsider their opinion. Soon they are dressing in fashions of the time. Gordo thinks it's cool that they like it, but hopes that his new interest won't become the latest passing fad at school. But that looks like exactly what is happening as Ethan soon has all the guys wearing hats like Sinatra and listening to the music. Even Kate is admiring the girls for being in first on the new trend and actually asks for their advice on what to do!

Lizzie, who is writing for the school newspaper, asks for the assignment of covering the school's production of Mr. Escobar's play ""Greasier."" Miranda is overjoyed when she unexpectedly gets the lead in the play. When Lizzie and Gordo go to rehearsal, however, they are dismayed to find that Miranda is a terrible actress, and clumsy to boot. Miranda is confident before the opening of the play, but her performance is no better and she destroys most of the props and scenery. Lizzie can't bring herself to write the bad review Miranda deserves, but Gordo thinks she'll be able to take it. Lizzie writes a review that is honest, but goes easy on Miranda. Her friend doesn't see it that way, though, and thinks Lizzie has betrayed her. At lunch they get into a big fight.

Lizzie is in a frenzy because Ethan Craft has asked her to sit with him at lunch the next day. But at home she still has to put up with bratty brother Matt, who put honey on the phone receiver and messed up her hair. Lizzie is furious with him and this time his parents are also very upset, too. They ground him and Mom says there will be more severe punishment to come. Matt races to catch the bus, but he gets on the wrong one, the junior high bus. Ethan Craft tells him to get out of his seat, but Matt stands up to him, which Ethan likes. He tells him his name is ""Bond...Matt Bond."" By the time they reach school, Matt has created a legend for himself as a child prodigy, actor, etc. and his reputation has already spread all over school.

The various obsessions of Lizzie, Matt and Gordo are driving friends, family, teachers and themselves to distraction. Gordo is intent on winning the Science Olympics at all costs against defending champion Larry Tudgeman. Matt becomes hall monitor at his school and gets carried away with his own power, giving out citations to schoolmates by the dozen and even trying to do the same to teachers and family members. Meanwhile, after she and Miranda work on a successful volunteer project at school, Lizzie becomes an environmental warrior, a fanatic for collecting clothing and food for the homeless, and even a vegetarian! All three learn that they must put limits on their fanaticism or else their original causes will suffer as a result.

Matt is irritating Lizzie with his magic tricks while she's trying to do homework. Soon they are fighting like cats and dogs--or brother and sister--much to the annoyance of their parents. But as soon as Sam and Jo stop them, they go right back to fighting. At school Ethan Craft speaks to Lizzie and Miranda, but Lizzie is so tongue-tied she can barely utter a word. Mr. Escobar announces a charity drive and asks for volunteers. Lizzie thinks she'll be too busy until she hears that Ethan will be there. At home Lizzie is making some cookies for the event when Matt tries out another trick. This time he handcuffs himself to his sister, but he can't get the cuffs loose. Mom spies the key and hides it, thinking that if the kids are forced to spend a few hours chained together, they might learn to get along better. Now Lizzie is facing the horror of going to the charity drive with her little brother stuck on her arm!

Lizzie's fantasy almost comes true when she is paired up with Ethan Craft in a CPR class at school, but he's so dense that the teacher chooses Tudgeman instead to give Lizzie mouth-to-mouth! Lizzie, Gordo and Miranda realize they are about the only three in school who haven't seen the latest blockbuster movie Vesuvius: The Eruption, which is rated R, and they're determined to get in to see it. When their parents all say ""no"" to their arguments, Gordo decides they should say they are going to play miniature golf, then go see the film. Lizzie is very nervous about lying to her parents, but she pulls it off with ease. The trio can't get past the ticket-taker, though, and can't slip in the back, so they mingle with the crowd as it is departing a showing and sneak in that way. While at the concession stand, they notice a man choking.

Lizzie and Miranda feel neglected, when Gordo spends more time with his new girlfriend, Brooke. They are unable to come to terms with the fact that Gordo has a girlfriend now and he is drifting away from their group. Meanwhile, Matt learns about "percentages" from his father and starts accepting bets from his friends, but he eventually lands in trouble when his mother finds out about this.

Gordo wants to raise money for a new stereo, so Miranda and Lizzie suggest he tutor students who need help in math. His first student is Ethan Craft, much to the girls' delight. When Gordo is working with Ethan at the Digital Bean, Lizzie and Miranda keep trying to horn in on the action and end up spilling drinks all over the guys' papers. Gordo gets mad at them and suggests that they aren't smart enough to help him tutor anyway. The girls get angry right back at him and leave. Meanwhile, Matt and his friend Oscar are looking for something exciting to do. They decide to become ""super heroes"" Matt Man and the Incredible Oscar. They go around the neighborhood in costume trying to do good deeds, but all they do is annoy the neighbors.

Ethan invites Lizzie, Gordo and Miranda to go bowling with friends on the weekend. Of course the girls are thrilled but Gordo isn't so happy--bowling is something he's not good at. In fact, he got so nervous doing it before that his fingers swelled up and the ball had to be cut off his hand! Miranda says she will be Gordo's ""life coach"" for bowling and tries to teach him him a kind of mystical philosophy (""Be the ball!"") Meanwhile, Matt and Lanny are trying to think of what they can do to stop the bully Heywood Biggs from picking on them. When Sam McGuire hears Lizzie talking about her sort-of date on the phone, he worries that he's not involved enough in his daughter's life. He asks her if she'd like for just the two of them to go out to dinner on Friday so they can spend some time together. Lizzie agrees, but later realizes that the bowling date is the same night! She decides she'll have to ask her father to reschedule.

Director Stan Jansen is filming a documentary at the junior high and everyone is trying to get on camera--except Gordo, who wants to be a director himself. But Stan singles out Gordo as his star and tells him his appearance in the film could lead to a career in directing. Gordo is eager to go along, so when the director tells him he wants conflict, Gordo trashes Kate on camera. Lizzie and Miranda think that's great, but it's not so great when Tudgeman gets upset after the same treatment. Then when Gordo manipulates Lizzie and Miranda into revealing long-held secrets about each other, the trio's friendship is on the rocks. The girls can't stay mad at each other, though, and they convince Gordo that their friendship should be the most important thing to all of them. The kids find a way to get back at Stan Jansen.

Lizzie auditions to be in a fashion show presented by "Teen Attitude" magazine at a local mall and she gets accepted. At the show Lizzie looks great on the stage. Afterward, popular girl Jessica asks Lizzie to come to a party at her country club. Lizzie gets Miranda and Gordo invited also. At the party, all three are enjoying the fun, including the hot tub. But already Lizzie's friends are acting different. When Jessica asks her about coming to another party, Miranda starts answering for Lizzie like a press agent and she and Gordo start negotiating future appearances for her like a supermodel! At school things are very different, also. Kids stare at her in the hall like she's a celebrity. Kate is now fawning all over Lizzie, wanting to be her friend. Ethan is so starstruck that he can't even mumble a coherent sentence around her. Gordo and Miranda are as bad as anybody. Lizzie muses, "Gordo and Miranda aren't my friends anymore. They're my people!"

The middle school is putting on a big Fright Night celebration for Halloween. Lizzie wants to appear as Vampira, the dungeon mistress, but Kate is in charge and she keeps the job for herself, making Lizzie clean out the janitor's closet and then giving her the role of a clown handing out balloons. Miranda brings her parents, who are helping her celebrate a Mexican holiday, the Day of the Dead. They bring by several items including skulls and skeletons which are meant to represent ancestors who are being honored. Kate is all smiles when Miranda's parents are around (""Toon Lizzie"" calls Kate ""phonier than cafeteria cheese""), but once they leave she yells at Miranda to get rid of that junk they brought. Miranda warns Kate that by disrespecting the dead, she is risking their wrath.