When Lucy calls Brian and Sophie "Mum and Dad", Mel gets angry and shows Lucy and Josh a box of things she kept to remind her of their real parents. However, a lipstick is missing from the box. Lucy realizes that it was she who had taken it and swapped it, so she must ask Josh for help. Meanwhile, after a string of Fs, Josh must resit his exams or be put back a year. To pay him back for helping with the lipstick, Lucy helps him revise, and discovers that he may be dyslexic.

When Lucy wins tickets to see Blink 182 in a competition, Josh is desperate to take them off her hands – after all, he's a huge fan of the band, and Lucy's such a geek she's never even heard of Blink 182. Lucy agrees to give the tickets to Josh, but on one condition: Josh has to perform a truly unselfish deed in order to qualify for the tickets. Of course it's a terrible struggle for the scam-meister, but Josh learns a whole lot about himself in the process. Elsewhere Mel is upset (though refuses to show it) when Trent appears to be going on a date with another girl. The confusion is resolved later in the episode when it turns out that Kelly is Trent's cousin, not his date and he and Mel become friends again.

Lucy is selected to represent the school in a Science Tournament where she has to build a rocket with maximum propulsion – which proves to be too difficult a task for her, so Sophie offers to help. Brian enters one of Mel's photograph's in an art contest. Josh tries to bribe Scott Taylor into letting him join the football team and get to go to Holland and almost loses Frankie and Pete as friends.

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 become hooked on a trading card game, and will go to any lengths to obtain more cards. They end up stealing and selling the school laptop. They then discover there is a rare card (Madonna) that they need to find. They find the card, but realise they have wasted their time and money. They feel very silly.

Josh fails his biology exam and has to retake it in 2 days. Brian goes to see Mrs Hardman and says he can do better and can make Josh clever. Brian morphs into Josh and does the exam instead. Meanwhile, Lucy is having troubles in the orchestra because she can't play her instrument and gives up.

When Lucy wants Brian's help with her magic act, his ambitions go far beyond being her assistant. Mel runs in the school's sponsored FunRun with Andy the freak in a pantomime horse costume.

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.

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!

Brian is desperate to join Lucy at the Brownies, but she refuses for obvious reasons. Undeterred, Brian forms his own association – The Brianies – with its own code of conduct. Meanwhile, Mel has got a job at the diner with Sophie later joining her to help her out...with some disastrous results.

Brian decides to give the attic, now filled with a bed, cinema screen, drinks cooler, &c., to the member of the family who loves him the most, but Lucy walks away from the contest, saying she loves Brian as a father, "no more, no less". Josh and Mel then compete in vain to win Brian's affections. Meanwhile, Sophie tries to boost her self-esteem. Based on Shakespeare's King Lear.

Lucy is horrified to find a wart growing on her face. But not as horrified as Brian, who has discovered the real purpose of the bath; he develops a taste for shower gel and is obsessed with hygiene-until he starts shrinking!

Sophie decides to accompany Lucy to advanced mathematics classes after school, but it soon becomes clear that Sophie has fallen in love with Mr. Whiteside, the teacher. Brian feels that he is losing Sophie (and her ability to cook disgusting meals which deeply satisfy Brian) to Mr. Whiteside, so he sneaks into school and kidnaps Mr. Whiteside, and then morphs into Mr. Whiteside himself, to try to pretend to Sophie that Mr. Whiteside is "evil". Unfortunately his plan is ruined when Sophie invites Brian and Mr. Whiteside to have a meal together with her.

Brian is out buying a bicycle, but ends up in a wheelchair. Not that he had been beaten up, but he loved the wheelchair and rejected the bicycle. Lucy overhears Wendy's Mum saying to Mrs. Hardman that Wendy only has four weeks to live. Meanwhile, Brian protests at the diner for disabled access and Mel is recovering from a mud mask that went horribly wrong and having to be guided round school by a guy called 'Francis'...which is actually Frankie!

Brian is still protesting for disabled access at the diner. But soon everyone notices that he is just lazy, until he actually has a wheelchair accident. Meanwhile Sophie changes places with the school rabbit so that Josh can get the reward money off Poppy Manning and Mel discovers that Francis is actually Frankie.

Mel heads for stardom as the presenter on the lunchtime programme on the school radio putting Trent's show out of the lime light. And because of Mel's success, Brian and Sophie learn what it is like to be fans and focus all their attention on... Mel. In the end, she is fired because of the resulting scandal with commentary at a sports game.

Sophie helps herself to a baby in the supermarket. Shocked the kids insist it must be taken back, which leaves Sophie feeling broody. Brian obliges her by morphing into a baby with...disastrous results and resorts to Sophie looking after another baby from the children's home. Meanwhile, Josh is desperate for a new games console and Lucy wants to buy some new clothes for seeing Bill Gates.

Dissatisfied with the level of affection his foster son is prepared to show him, Brian creates a robot double of Josh... and causes total chaos. The robot Josh in one scene parody's Johnny from The Shining.

Josh finally manages to land a date with gorgeous Tania Thomas, the girl of his dreams, but it soon goes all wrong after Brian & Sophie have created a super strong glue mixture. This is one of the two episodes where the Bathroom in the Barker-Johnsons household is seen.

Josh's latest scheme ends in detention after he sells a computer password to Frankie, while Brian watches a series of sci-fi films and discovers the general public believe aliens to be bad guys – so he sets about changing people's opinions.

The children are outraged to discover Sophie has put them up for sale on the Internet – and what's even more mortifying is the price she's asking. The family also get involved in the school charity fair, where Mrs Hardman ends up dancing with three different Joshes.

Lucy grumbles that her school work is too easy, but is horrified when Brian and Sophie tell her teacher about her complaints. Brian organises a break-in into the school in order to procure Lucy's school report, while Josh sets up an online dating agency and Mel encourages Trent to emphasise his masculinity

Josh builds up his muscles to impress a sporty girl, but Brian's attempts to help him land a date with her end in disaster. Sophie leads a classroom revolt against her teacher, and Trent blackmails Mel over a pair of pants.

Brian is excited about what he will get for Christmas until he finds out that Santa has a "naughty" list, and he's afraid that he may be on it. Meanwhile, Sophie is trying her best to find out what Lucy has got her for Christmas and Josh is looking after Frankie's present from Pete.

Josh, Pete and Frankie are in competition for the attention of a new girl in school, but there's a surprise in store for one of them when they discover who she is. Mel has left for Canada and Brian is suffering in her absence, so takes matters into his own hands by getting a 'new Mel' from the children's home, while Lucy is enjoying having a room to herself, which soon changes as CJ starts launching desperate attempts to move in, even resorting to 'becoming' a girl!

"Great Versace's ghost!" Brian cries as he takes the role of fashion designer and forces the children to wear his fruity clothes and curtains. Meanwhile, Sophie collaborates with Josh in yet another fraudulent scheme, this time a pet selling scam involving a pot bellied pig, and a lot of icecream...

Josh and Brian vie to see which of them can tell the scariest Hallowe'en story, but Sophie can't understand why it's fun to be frightened.

Sophie decides that she must become a nanny in order to see more of the children. Meanwhile, Mr. Whiteside thinks he's seen a ghost after Brian morphs into the spitting image of a long-dead former school headmaster. Lucy, worried about a test, downloads an alien virus into the school computers however this takes a downward turn.

All the children are revising for exams (apart from Josh – obviously, he has stolen all the answers already). Then, Josh finds out that he has won a year's supply of chocolate. Brian is delighted and becomes addicted to it, but all the children ban Brian from eating anymore. Brian is furious when a tube of chocolate falls out of Josh's pocket and he finds out Josh has been eating chocolate when he can't. So he declares: "If I can't have chocolate, then no-one can!". He sets himself up as a South American military dictator, prohibiting "chocolate and/or cocoa related products", and enforcing the ban with by imprisonment and torture, notably on CJ. Meanwhile Lucy tells Sophie that sometimes stress can help people perform better, so Sophie becomes an Austrian psychoanalyst, stressing Lucy with seemingly random violence and explosives.

Sophie learns about gossip and thinks that Mrs. Hardman and Mr Whiteside have fallen in love with each other. Brian finds a human toe in his can of cola and finds out the drink was faulty and complains before he tests CJ’s eyes and discovers that he too is ‘faulty’. Josh competes in a snail race against Poppy, and the winner gets £5. Josh is convinced he'll win but when his snail is about to win Mrs Hardman comes in and Josh accidentally sits on his snail (Lenny) killing it.

Mel finds out that the children have or had an aunt and uncle in Canada who look suspiciously like Brian and (the original) Sophie. They confront Brian and Sophie, who admit that, seven years ago, they met Josh, Mel and Lucy's aunt and uncle at the children's home – and then, after the aunt and uncle realized that they were aliens, the aunt and uncle were kidnapped and kept in suspended animation in the attic for seven years. The children insist that they let them free. Meanwhile, Wendy discovers Brian and Sophie are aliens, and she tells Pete and Frankie too, so Brian wipes their memories. Everyone realizes that it is time to move on. Josh, Mel, Lucy, Harry and CJ all move to Canada with the real Brian and Sophie Johnson, and the aliens appear to go back home to Valux; however, Brian presses the big red button that caused the pair to crash-land on Earth in the first place setting the stage for series 8. They land by the sea and then head for the foster home.