It's the Casson Family finale, and Permanent Rose takes centre stage. It's tough being the youngest - Rose is lonely.
Her family are always busy doing their own things so Rose comes home to a dark, quiet, empty house every day.
Saffy is off with Sarah, Indigo has his paper round and guitar lessons, Eve's in quarantine in the shed, Bill's not much use in London, and who knows where Caddy is since she disappeared with Michael's postcards!
The only one around is David and Rose would rather be alone than be with him! At least Rose still has her friends at school: the brilliant Kiran and the nice but boring Molly.
But school is no longer a peaceful place where Rose can daydream.
Mean Mr Spencer is always shouting about SATs. And now he's cancelled Christmas! But one thing Mr Spencer cant cancel is the Christmas School Trip which means Rose can help Molly with her ONE BIG IDEA ... but what could that be? Will it be a very merry Christmas for Class 6 and the Casson family?