When Casey (Ashley Leggat) is forced to share a room with her little sister Lizzie (Jordan Todosey), Casey decides that she needs a room of her own or rather, Derek's room. Casey suggests that since she's had to leave her old life, school and friends, that it would only be fair if she was given Derek's room.

Tired of having no space for any of her stuff, Casey (Ashley Leggat) proposes that five valued areas of the house are shared among siblings. With no intention of sharing, Derek (Michael Seater) suggests playing games of chance to decide which team - the MacDonalds (Casey and Lizzie) or the Venturis (Derek, Edwin, Marti), wins.

When Casey (Ashley Leggat) humiliates herself by falling on top of her new classmates in the school hall, right in front of Derek's best friend Sam (Kit Weyman) on whom she has a crush, Casey gets the embarrassing nick name: Klutzilla.

When Casey (Ashley Leggat) and Derek's (Michael Seater) parents decide to go away for the weekend, Casey and Derek must convince their parents that they can be trusted to take care of Edwin (Daniel Magder), Lizzie (Jordan Todosey) and the house without a babysitter, but Derek has other plans!

Chaos in the house prompts Casey (Ashley Leggat) to implement some basic house rules. Meanwhile with Nora (Joy Tanner) away at a retreat, George (John Ralston) needs to enlist everyone's help to organize the book club happening in their house that night.

Nora (Joy Tanner) and George (John Ralston) need a babysitter for an upcoming day trip and Derek (Michael Seater) ends up being left in charge of Marti (Ariel Waller) who has fun terrorizing him as he tries to impress the new girl from school, Sandra (Claire Hewlett).