Rosie lives in a playhouse with her colourful group of friends. Together they embark on adventures as they learn the meaning of true friendship. Oakley plays with his echo. Every time Oakley blows a raspberry, the echo cheekily blows one back. Rosie and Raggles soon realise that other strange things are happening. The Twooter mysteriously moves, Big Bear wakes up with chalk glasses drawn on his face and Bluebird's Bozberries have a life of their own. Rosie suspects Will is up to no good - is Will responsible for the pranks, or does the echo want to come out and play?