Brian and Sophie find a huge Christmas tree. Without knowing how much energy it uses up, it threatens to blow up the spaceship. Eddie gets his confiscated Christmas present back and Jaq comes back home. Dan, Becky, Eddie and Jaq need to de-frost Brian and Sophie. After de-frosting them the meltdown only has 30 seconds left. Sophie's too frightened to press one of the four buttons and with three seconds left will the spaceship blow up or not? At the last second someone presses a button, but who is it and is it the wrong button??
Sophie rescues Jaq from a surfing accident, and soaks up the praise that accompanies her heroics. However, to regain the warm feeling it gives her, she engineers more and more dangerous trials for the youngster to face in order to save the day once more.
Brian has the crazy idea that having a cold will be really fun, so he gets Becky to infect him. However, his first sneeze blows over the furniture and then he turns into a puddle of snot.
Brian tries to make Dan a hero by staging a series of fires in the school toilets, while Sophie manages to fill the house up with piles of rubbish.
Brian discovers a treasure chest, and sets out on a mission to splash the cash. Meanwhile, Sophie confronts a teacher that has insulted aliens, and Eddie breaks his friend's new computer.
Brian embarks on a miniature crime spree, ordering Eddie to steal all of the cakes he can get his hands on. Meanwhile, Sophie tries to become the perfect mother. Sophie bakes the best cake in the world for Dan. Brian wants it – and tries to persuade Eddie to help him steal the big creamy pile by murdering Sophie.
Sophie and Brian try to act like normal human beings – though unfortunately he opts to be the model wife while she wears the trousers. Brian is being operated on by Becky and the family. Becky needs to get some of Brian's insides in order to stop the mutated flu virus melting him.
Sophie turns the living room into a pleasure beach. However, Brian's attempts to have fun have miserable repercussions for Eddie, who ends up buried in the sand.
Sophie's involvement with an international crime ring puts the family under threat, while Brian believes a visiting exchange student is a fellow extra-terrestrial.
Sophie develops an interest in darts and is delighted when Eddie manages to score a bull's-eye. However, the youngster soon finds himself under so much pressure to perform in a competition that he struggles to throw straight. Meanwhile, Jaq finds herself in trouble with Brian after daring to complete his jigsaw puzzle.
Jaq's arch-enemy Selena is drafted in to look after the kids, but when Brian and Sophie come home, she refuses to leave the house – calling for help
Brian plants a bug in Jaq’s mobile phone to keep track of her every move and Sophie decides that Eddie would be the perfect little dolly for her to play with...
Brian and Sophie decide they need to make a new friend – and with the children starting school, a teacher seems the perfect choice.
Brian and Sophie crash-land by the sea and find four more children to foster – however their memories of the past seven years are wiped by Guido, the new avatar for the Galactic Guidebook, and are now unsure of how the new members of the family will react to the news of their alien identity.
