Helena is big-sister mouse to three younger siblings, living a snug and well-fed life within the ancient walls of the Cranston family home. When the Cranston humans decide to sail away to England to find a husband for one of their daughters, the Cranston mice stow away in the name of family solidarity.     And so begins the scamper of their lives as Helena, her siblings, and their humans set sail on a life-changing voyage into the great world of titled humans . . . and titled mice, and surprise endings for all. On the eve of Queen Victoria’s diamond jubilee, will our Cranston heroes squeak by, or will they go entirely overboard?