An all-new story in comics! It's double trouble for America's favorite girl detective when Owen Zucker, a sweet young boy Nancy has often babysat, is missing, and - a shorestone marker found on the coast of California, which may prove the Chinese discovered America before Columbus, is stolen! Will Nancy, with the helo of her best friends Bess and George, be able to solve two baffling mysteries at the same time, while all of River Heights is watching?