The Gang discover a prototype hover mower whilst clearing out Bob's shed. The major design fault is obvious when it burrows into the ground, creating a tunnel that leads all the way from the back garden to Australia. A shouting match with some dingos follows, at the end of which an enraged Bob accidentally throws Vince down the hole, precipitating an adventure of global proportions.
Rex takes a much-needed holiday, and leaves Bad Bob in charge of the adventure for this week. The story involves 'The Beast of Granite Moor,' to which Bob, Wendy and Vince cast a 'rather wooden' Zebra for the role of the Beast. Luckily for them, the Zebra had played the role of 'The Beast of Granite Moor' in a previous production.
In this homage to Rebel Without a Cause Bob joins a gang of delinquent youths. He takes to wearing a single glove and one of Wendy's earrings. Wendy, Rex and Vince are worried by the change in Bob's character. When he gets arrested they hope he will see the error of his ways, but it only makes a life of delinquency seem more glamorous to him.
Wendy has been nominated for the Nobel Prize for Science for the truth serum she's been working on in the spare room. The dress code on the invitation to the award ceremony says Scientific yet sexy: no white coats and Wendy decides to get her hair done. While she's out Bob and Rex consume the serum, which makes for a revealing afternoon particularly when Wendy returns and they tell her she's bald.
After a row about whether to spend the bank holiday at the beach, the Gang end up at Gordons Garden Centre where Vince is taken hostage by a talking carnivorous plant. Things go from bad to worse when the whole place turns out to be a giant spaceship controlled by a deranged alien plant-pot called Gordon, bent on kidnapping all earthlings named Gordon.
Wendy's on heat and the Gang's house is besieged by amorous hounds. The Gang draw down the blinds and prepare to repel borders, but one dog, Handsome Rex catches Wendy's eye and she agrees to go out on a date with him. Vince and Rex insist on chaperoning her. By the end of the evening Rex has made a new friend, Vince has fallen in love with a lobster, Arthur Dustcart's had his underpants cleaned and Wendy's in a very bad mood.
Rex arrives home to find that there's a mouse in the kitchen. But this is no ordinary mouse, he is preternaturally strong, extremely aggressive and refuses to be kicked out. The Gang even resort to getting Tiddles the Cat round to sort him out. Then the mouse reveals that he was once Rex's pet mouse, Morris, who Rex sold to Dr Dogg for animal experimentation. A tearful reunion ensues.