On the day of Rosie's fourth birthday, she receives a huge silver balloon attached to a book about rainbows from Grandpa. Rosie takes her balloon outside for a ride on her bike but its tie becomes loose and it soars high into the sky. Very upset, Rosie calls her grandpa to see if he can climb on his roof and catch her balloon because it's heading his way. That night, Rosie reads her rainbow book and dreams about her balloon travelling on an incredible colour-changing rainbow adventure. This story not only shows the special relationship between Rosie and her grandfather, it also displays the colours and order of the rainbow spectrum. Does Rosie's balloon come back to her? You'll have to read this book to find out.