Sixteen-year-old Grace lives under a bridge in Melbourne's CBD. It's cold and wet, but hidden. Safe, at least, until she can go home. When winter drives her to the City Library one morning, Grace meets Louie, a weird kid with his own problems, and discovers a community piano. The piano reminds Grace of her mum, a celebrated pianist whose mental illness makes life a rollercoaster and not always a fun one. When Grace comes up with a plan to find the help she and Mum need, life begins to look up. But things don't work out as Grace imagines and suddenly her world's turned upside down again, and maybe for good this time.