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...

Harry gets angry with Sophie for not providing for her properly, even though she is doing the best she can. The example of this is Cold Scrambled eggs. This gives Sophie the idea of opening a hotel, so that she can at least get paid for running around after people. Guests start to arrive at the house, and Brian causes chaos by messing with the central heating.

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.

After CJ nearly chokes on a gobstopper, Brian decides to learn some first aid in order to keep the family safe. After injuring the school nurse, he morphs into the replacement and Mr Whiteside falls in love with him. Josh meets a girl but when he realizes that she is a psycho, pretends to be gay, going out with Pete until he finds out that she is rich. Lucy tells the girls in her class that she wants to get her nose pierced making her instantly popular... until she reveals that her piercing is a fake! Because of this piece of metal she goes from −100 to hero...and straight down again!!

After worrying that he will not be remembered when he dies, Brian goes on a quest to find the Holy Grail with CJ. Josh participates in work experience at the diner. Wendy and Lucy start a company producing potato powered clocks, and Sophie helps make them, however, she is told off by Lucy for giving them all away free. Sophie then founds "Sophie.com International" which sells useless coconut toys, yet these are a hit. Her business is about to go international until Lucy discovers she is enslaving children to make the toys.

Harry signs up for a boxing tournament after Trent says girls shouldn't compete in the sport, but her confidence takes a knock when she sees her opponent. Brian is bullied by a little schoolboy and Sophie dresses up as a hamburger.

Sophie tries to help Josh woo Tania by turning him into a talented musician. Brian is introduced, by CJ, to the ancient Roman concept of fascism and quickly imposes his own absolute rule on the household to get his way – idea of democracy and declares himself emperor of the household.

When Harry cooks Brian and Sophie a romantic meal to help them patch up their differences after an argument, the aliens quickly go to the other extreme and become totally wrapped up in their passion for one another, (much to the children's embarrassment). However, when Josh tries to cool their ardor, Brian becomes convinced that he's trying to steal Sophie's heart. Meanwhile Lucy is up for a prize at school... until Brian and Sophie take it too far.

Lucy is due for a vaccination at school and it becomes evident that uncharacteristic though it may be for her, she is dead scared. After Mr Whiteside pickpockets Josh's music player and drops it in his tea, Josh uses Brian and fixes everyone's electronics for £5. Mr Whitside also asks him to fix his. Brian ends up destroying everything, including Mr Whiteside's gadget! Sophie gets into photography and pursues all the kids around the house in attempt to get some candid shots. But when she takes it upon herself to capture Lucy's fear as she waits for her injection at school, she unwittingly motivates the kids to turn the tables on her. Brian, fed up of always being criticized for his behaviour, decides he is only going to do as he is told and adopts an attitude of total subservience. But he can't anticipate how complicated it can get when he tries to obey orders from one person, especially when that person is Josh.

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.

Confused by ideas of right and wrong, Brian decides wrestling is the best way to settle arguments. Meanwhile, Sophie is given the opportunity to eavesdrop on Whiteside's private moments.

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.

Josh needs an alibi from Harry to cover himself from some misdemeanor, but Harry of course refuses. Trent advises him he might have more success if he broke a habit of a lifetime and tried being nice to her. He gives it his best shot-but to no avail. Sophie causes Lucy yet more embarrassment-this time at the swimming baths where she makes a fool of herself sinking instead of swimming. Sophie takes herself off to the river to practice and morphs a spectacular tail but fails to morph back owing to the pollution of the water. As a result the family have to cope with a new Sophie in mermaid mode. And she has a spectacular effect-not least on Andy The Freak. Fed up with losing to CJ from Hide-And-Seek, Brian changes the geography of the house and causes chaos for the whole family. This is the only other episode where the bathroom in the Barker/Johnston household is seen.

Brian's hostile behaviour puts the family at loggerheads with their new neighbours, Brian doesn't get on well with them since he eats their roses (calling it 'The War Of The Roses') – which proves unfortunate for a love struck Lucy.

Brian buys a racing pigeon for Harry. The pigeon is called Humphrey and Harry likes him for the outset. When Humphrey goes missing, Brian is blamed, so he tries to make things better by morphing into Humphrey himself. Meanwhile, Sophie morphs into Josh and sets up a stall selling stolen medical supplies. This gets Josh into a massive amount of trouble but Sophie saves the day by making Mr. Whiteside let Josh out of the punishment. When this problem is sorted there is one more problem to be solved, Harry entered Brain as a pigeon into a race where he has to make it home again from the starting line and he hasn't found his way home for days. Three days after Brian was sent into the race he returns to find that everyone loves him and is glad to see him.

Harry does her best to stop Brian and Sophie inviting Trent's parents to tea. Harry learns a "shocking" secret about Trent, Sophie gets into growing vegetables and Brian gets into football.

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.

Sophie has discovered how pollen from flowers can give you hay fever and almosts destroys all plants. But with an explanation from Lucy about how flowers are good for the atmosphere and for bees to make honey, Sophie decides to set up a bee sanctuary in the house. Meanwhile, Brian (morphed as Josh) has ruined Josh's reputation by becoming Mr. Whiteside's school monitor and putting people like Harry, Frankie and his date Tania Thomas in detention.

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.