Mel gets a job offer as an assistant to a fashion photographer. However, her audition takes place during school, so she goes to the audition whilst Sophie (who is not a very gifted morpher) morphs into Mel and goes to school. Unfortunately, she goes around kissing everyone, including Trent, Frankie and Mrs. Hardman. She is referred to a child psychologist. Sophie panics when seeing the psychologist and Mel arrives to take over. She soon transforms to a lady with Red hair to make sure the psychologist doesn't see there are two Mel's. However, Sophie cannot morph back to her original human form, and decides to keep another look, thus introducing a new looking Sophie (Carla Medonça).

Brian and Sophie are not technically married, so Lucy arranges a wedding to bring the family closer together, but her grand ideas are nothing compared to Sophie's. Brian learns it is hard to choose a best man. When Mel gets angry about the wedding, they decide not to have a proper wedding, but a friendship ceremony instead.

It's Valentine's Day, and Josh is trying to get a date with Tanya Thomas, but makes the foolish mistake of taking Brian's advice on matters of the heart. Mel is the object of desire of Andy the Freak and Frankie when all she wants is a 'joke' Valentine's card from Trent. Sophie follows her heart and writes a card to her true love: the dishwasher. Sophie asks the family what Valentine's Day is, but in an episode a few years ago when Barbara Durkin played Sophie she is trying to act calm in front of a teacher who has come to visit the house and she says "This happened to me once on Val.... Valentine's Day".

An alarm sounds in the household – signaling that there is a Valux rescue ship nearby. Brian and Sophie are faced with a difficult decision: go home, or stay with the children. The children are horrified that they might be abandoned again and recall (in flashback) the day they were fostered by a very different-looking Brian and Sophie. Lucy was desperate for a family, Josh was still looking for fringe benefits and Mel was desperate to avoid disappointment. Can Brian and Sophie be persuaded to keep their family together?

On Halloween, Josh has a plan to run a tour of the school, with Frankie and Pete helping to spook the students. Mel wants a Halloween party but is so scared that no one will turn up that she advertises the event as Trent's party. However, no-one wants to come a party held by Trent either and the two of them turn out to be the only ones there. During this episode there is one of the many obviously romantic moment between Mel and Trent when they almost kiss in Mel and Lucy's bedroom.

When Lucy gets in trouble with one of her teachers for apparently copying homework, Brian and Sophie discover the power of punishment. Poppy writes an article in the school magazine criticising Josh. Mel accidentally kills the school budgie and Josh writes this in his own school magazine. To get revenge, Mel gets Brian to morph into Josh and take naked pictures of himself to give to Poppy to print in her magazine.

Brian has a new pet: Fluffy the goldfish, but when she's fed on a diet of fried egg, bacon and beans, the unfortunate Fluffy soon floats off to the big fish tank in the sky, leaving Brian devastated. He then holds a funeral for his beloved Fluffy, which goes well. Josh attempts a challenge at the diner: eating 50 courses. He asks Brian to morph into him, and eat 48 of the courses. The first course is fish fingers, devastating Brian. He quits, leaving Josh to eat all the food. Mel later takes out insurance with dozens of spare goldfish, which she stores in the bathroom, and Brian thinks that the new fish is Fluffy back from the dead.

Josh is confident that his "treat 'em mean, keep 'em keen" tactics will eventually win the heart of his school friend Tanya. Sophie decides that humans tell lies all the time, making her highly suspicious of everything her family says. Mel persuades Trent to let her stand in for him as school magazine agony aunt, but can she really summon up as much sensitivity as he does? Mel's determined to prove to him that she can. In a desperate bid to prove to Josh that he can lie convincingly, Brian tells Pete that Tanya fancies him. But when Pete and Tanya arrange a date, Brian has some quick thinking to do before Josh's heart is broken. Brian discovers that lying can cause a lot of trouble, while Mel finds out that telling the truth can, too.

Josh is woken by a trumpet-playing Brian and is offered tiddlywinks for breakfast. His sisters may be technically human but they still can't behave like normal people. Why can't his family just be different in every way? A bump on the head makes Josh's wish come true, throwing him into a world of complete opposites. Lucy is stupid, Mel cares about what she looks likes and fancies Frankie, Sophie doesn't even try to be a good mum, Pete is short and fancies Mel and Frankie is tall doesn't like Mel but all of the other girls fancy him. Wendy is his girlfriend and like Lucy, is thick, but more clumsier than Lucy. And Mrs. Hardman is the art teacher and fancies Brian. This leaves a whole world of confusion and he wishes that he could have been fostered by someone else.

Meanwhile, the opposite Lucy and Wendy, are trying to write a story to win a day with Chubby the Bear but don't write much. And when Sophie enters too, Josh has to stop her from entering.

Lucy and Wendy have an argument that might end their friendship for ever. Josh has laryngitis, but despite Sophie's best efforts to nurse him back to health, he quickly loses patience with her bedside manner. Sophie finds that being ignored can make you feel like you don't exist at all. Brian is jealous that Trent has given Mel a music festival ticket and morphs into 'Spam' – a hip and trendy girl that will catch Trent's eye. His plan works, but Mel is devastated that Trent has found someone else. Can Josh and Sophie persuade Brian to make amends before Mel's heart is broken and Sophie turns invisible from a lack of attention? Wendy moves to Birmingham for a few months.

With Wendy away, Lucy is lonely and Mrs Hardman invites her to audition for Oliver, the school musical. Brian studies musicals by renting them all on tape. He sees that Oliver is an orphan like Lucy he thinks that this has caused offense. He speaks to Mrs Hardman and pulls the trapdoor lever so Mrs Hardman falls and breaks her legs. Brian resurrects the musical as BRIAN: The Musical. Sophie thinks that Josh has Parental Neglect Syndrome and follows him around school. Sophie then watches the Sound Of Music and learns how to really be a good mother. Mel has a bet with Trent that she couldn't last four days without insulting anybody but in the end it is Trent that breaks first and begs Mel to be mean again because that's the way he likes her!