Author: Mary Pope Osborne
Format: Hardcover
Published: Random House, 2006

From the publisher: Jack and Annie are off on another Merlin Mission. This time, Merlin has sent them to rescue a beautiful magical creature—the unicorn. But when they land in New York City during the Depression of the 1930s, Jack and Annie are confused. Where will they find a unicorn in a big city? And what about the blizzard that's burying New York in snow? Can Jack and Annie make their way through the windy streets, find the unicorn, and maybe even bring some hope to the people of the great city? Only once in a blue moon do all the right elements come together to make magic in such a special way.