Lauren is finding fitting in to Australia a bit too hard. She had just moved from Canada with her mum, and now she's with her stepbrother and stepfather. But one night, there is a crash, and Lauren gets two house guests - Horace & Tina!
Lauren gets anxious for Horace & Tina to leave. So when she sees a poor wombat trapped in a cage, she takes this chance. After showing it to her mum, Kimberley takes the wombat out and cures. Taking this opportunity to get rid of Horace & Tina, Lauren tries to push Horace into the cage, but it doesn't work, and Sherlock gets stuck.
Lauren is sad because she hasn't got any friends yet. So she tries to become friends with Annabel. Unfortunately Horace throws a ball out the window and it hits Annabel, meaning she to hate Lauren, thinking it's her. But when Lauren joins in for softball Annabel sees how good Lauren is at it, but also sees some crazy things.
Lauren has to go back a grade seeing as she failed a test, meaning she won't be in a class with Lachlan & Annabel. But Lachlan has the perfect idea: to make Lauren play violin!
Tina would give anything to watch her favourite soap opera, so she asks Horace to cause havoc downstairs, leading to people trapped in closets, people falling over, and the fire brigade arriving!
Lauren discovers that Margaret can't read, meaning she doesn't know what price all the groceries in the store are. Yet, Steve doesn't know. So Lauren comes up with a brilliant plan!
When Max finds out his all-time space hero isn't coming to his birthday party, he is torn. So Lauren, Horace & Tina cook up an amazing plan to freak every space monger out!
Horace wreaks havoc in the neighbours houses and gardens, but everyone thinks it's Sherlock, because they can't see Horace. One night Sherlock howls and barks because there's a robber, but no one believes him. But what happens when the robber tries to rob the veterinary where Sherlock & Horace are?
Lauren & Lachlan's relationship continues to rise, and Annabel tells them both to go on a date. So at Lauren's home, they watch videos. But Max, locked up in his room, decides to spy on them. Only to witness Lauren speaking to nobody - but somebody (Tina) answers back.
Horace & Tina come down with a serious Nelf illness, and if they aren't cured soon, they will be visible to the naked eye forever! The only cure is Ice moss, which turns out to be broccoli - not Horace's favourite food!
Lauren goes into the Music competition, but jealous Alicia tries to stop her.
Max & TJ try to find all the answers of what's hidden in Lauren's room by looking in Lauren's diary!
Lauren misses her family and friends in Canada, so she decides to go back. But when TJ & Max capture Horace, she must save them, therefore leading to missing her plane.
Annabel & Lachlan hate Lauren for saying she'd leave for Canada, and when they have to go on school camp together, they hate it. But it's good for Alicia, meaning she can take Lachlan for herself.
Annabel decides to throw a lunar eclipse party with Lachlan & Lauren. But Lauren keeps rushing out of the party when Tina is in trouble - but most of the time, Tina's just testing.
It's Nelfen Day, that means Horace & Tina must grant everyone's wishes! But when Max wishes to know what's in Lauren's room, Tina must grant it!
It's Steve & Kimberley's wedding anniversary, so they decide to have a fantastic dinner. But Lachlan's first band gig is on at the same time, so Lauren must secretly go out to the gig without being noticed by her parents for leaving dinner early.
Tina falls in love with Ern, but Ern can't see Tina, so Tina sets Ern up with Svetlana. Meanwhile, Spike & TJ steal Max's bike, and he tries to get it back with no luck.
Lauren needs a motor for her project so she takes it to school. But Horace steals it, ruining the whole project, done by Lauren, Lachlan & Annabel. So, Lauren must go to the school psychologist and she tells him everything about Horace & Tina. This leads the psychologist into looking into Lauren's room, where a masterpiece is unravelled.
The house is getting a make-over, and so is Horace's new toy. He decides to paint it green, but his hands become green while trying, which means they're visible.
Max wants to become the next Zambini (famous magician). And when Zambini's manager comes up to him asking to be on Zambini's show, Max's dream becomes a reality. But his tricks only work with the help of Tina, meaning that when Tina's not there, Max's tricks don't work!
The School ball is coming up and Rory asks Lauren out after Alicia refuses, which causes a few problems between her & Lachlan. Meanwhile, Horace steals a toy car from a kid's house.
When TJ's railway parts go missing at the Tate's house where he secretly brought them, he & Max try to shoplift leaving Max the one who gets caught!
Dee, Lauren's best friend from Canada, arrives in Australia, only to be jealous of Lauren having Annabel & Lachlan as friends. So she tries to steal them, lying about Lauren.
Horace is making a new toy, and he needs the battery in the fridge of Steve's shop. But after Horace must leave the shop, the fridge catches on fire and burns the shop. Unfortunately the shop wasn't insured so Steve says they'll have to sell the house. Meanwhile, Tina creates a new screensaver about Horace, and Horace uses the battery to make his new toy. The buyer's son comes into Lauren's room and tells Lauren about how his father is going to tear this place down and turn it into a tennis court. Luckily, he sees the screensaver of Horace and loves it forcing him to want to buy it. But Lauren won't sell. Later on, Lauren goes to the buyer, a wealthy manager, and asks him not to tear down the house, when his son sees Horace's new toy. So Lauren says she'll give the toy to him for the price of her house!
It is Christmas Eve, and time for Lauren to say goodbye to Horace & Tina. But everything goes terribly wrong when Horace is trapped because Max & TJ are trying to catch him. They're almost successful when Lauren can't take it anymore and tells Max everything about the Nelfs that have been hiding in her room. This makes Max trick TJ into running away, and letting Horace & Tina go with Santa Claus back to the North Pole. But later that night, Horace & Tina return in the house and say they'll be staying for another year. And amazingly, Max can see them!