Mum Jazz decides to take Billy Bob to a doctor. Lucy and Louis are very happy because they think the doctor will finally tell Mum that Billy is an alien.
The Jenkins family accept Uncle Rich's invitation to spend a relaxing weekend in his spa, where the twins, seeing patients immersed in mud, believe they have ended up in the clutches of the mud monsters.
Little Billy Bob is getting his teeth and spends days crying, keeping everyone awake. Louis and Lucy believe an invasion of vampire aliens is underway who, with the help of their little brother, have turned the lord family into zombies
The twins think that BB3B is controlling people through the smell from his nappy, and with their group of friends set about trying to save the world from this alien hazard.
Grandma wants to participate in a beauty pageant and rejuvenate herself. The twins are convinced that it is possible to go back in time and decide to build a machine that takes them back to when Billy Bob was not yet born
The twins discover BB3B's plan to communicate with fellow sprogs in outer space via his baby monitor. Chubba's work experience at NASA doesn't go according to plan, and nor do any of dad's latest inventions.
Louis and Lucy discover that their favorite actor, Rex Philes, is in town and go to great lengths to meet him. They manage to drag him to their house and want to convince him that Billy Bob is a dangerous alien.
Lucy and Louis receive a virtual reality helmet as a gift from Uncle Rich. The twins become convinced that their uncle is an alien creature, just like Billy Bob, and that his purpose is to use his creation to take over the world.
Louis and Lucy want to find out how little aliens like Billy Bob are born. Mama Jazz then decides to accompany them to the hospital where Aunt Bibba is about to give birth. Louis and Lucy are convinced they have ended up in a spaceship.
Lucy and Louis believe they are the protagonists of a journey into space, on a planet light years away from Earth. Actually mom Jazz and dad Simon have organized, without their knowledge, a trip to Space City, a new "Space" amusement park.