After Brian accidentally leaves the front door open, Brian and Sophie come home to find all their furniture stolen. Brian responds by morphing into 'The Cat' to steal furniture from other homes, and this becomes his latest hobby. Josh discovers Brian's secret and (predictably) uses it to his own advantage. Meanwhile, Sophie becomes obsessed with home security, putting traps everywhere (which are mostly triggered by the Josh rather than burglars) and fears about the burglar worry Lucy so much that she begins to wet the bed.

Sophie decides to accompany Lucy to advanced mathematics classes after school, but it soon becomes clear that Sophie has fallen in love with Mr. Whiteside, the teacher. Brian feels that he is losing Sophie (and her ability to cook disgusting meals which deeply satisfy Brian) to Mr. Whiteside, so he sneaks into school and kidnaps Mr. Whiteside, and then morphs into Mr. Whiteside himself, to try to pretend to Sophie that Mr. Whiteside is "evil". Unfortunately his plan is ruined when Sophie invites Brian and Mr. Whiteside to have a meal together with her.

Brian dreads the arrival of April Fool's Day, convinced Josh is bound to play a practical joke on him – but Sophie welcomes it, eager for the opportunity to have a little harmless fun at Lucy's expense.

Brian is out buying a bicycle, but ends up in a wheelchair. Not that he had been beaten up, but he loved the wheelchair and rejected the bicycle. Lucy overhears Wendy's Mum saying to Mrs. Hardman that Wendy only has four weeks to live. Meanwhile, Brian protests at the diner for disabled access and Mel is recovering from a mud mask that went horribly wrong and having to be guided round school by a guy called 'Francis'...which is actually Frankie!

Brian is still protesting for disabled access at the diner. But soon everyone notices that he is just lazy, until he actually has a wheelchair accident. Meanwhile Sophie changes places with the school rabbit so that Josh can get the reward money off Poppy Manning and Mel discovers that Francis is actually Frankie.

Josh introduces Brian to a weekend of slobbing and Mel teaches Brian about manners. Josh bets with Mel that he can turn Brian into a gentleman and he does it, but Brian turns into an old grump. Also he invites Trent (whom Brian calls 'Trentington') round for dinner with disastrous results. So now, they've got to make Brian back to normal.