A new chapter book series featuring the stars of Disney's Frozen finds Elsa using her magical powers over ice and snow, and Anna following her own adventurous, loving spirit to explore their home and kingdom. When Oaken invents a new contraption to harvest ice, Kristoff challenges Oaken and his machine to a contest. But the next day, the engine and ice harvesters have gone missing. It is up to Anna, Elsa, and Olaf to find them. Book #4