Bells is always writing to her sister Katie, but Katie never replies. Preoccupied with her glamorous career in fashion, her busy life and her boyfriend Sam, she just doesn't have the time.

Then Bells announces that she's coming to stay. She's not a secret exactly, but. . . Sam doesn't know she exists.

For Bells doesn't fit into Katie's perfect world.

But when Bells does arrive, everything changes for Katie. Perhaps her perfect life isn't so perfect after all?