Joining an expedition to chart the southern seas, twelve-year-old mapmaker's assistant Sai, posing as a well-bred young lady with a glittering future, realizes she's not the only one on board harboring secrets when she discovers the ship's true destination.

In 1887, the social-climbing Cranstons voyage from New York to London, where they hope to find a husband for their awkward older daughter, secretly accompanied by Helena and her mouse siblings, for whom the journey is both terrifying and wondrous as they meet an array of titled humans despite their best efforts at remaining hidden.

With Nazis bombing London every night, it's time for thirteen-year-old Ken to escape. He suspects his stepmother is glad to see him go, but his dad says he's one of the lucky ones - one of ninety evacuee boys and girls to ship out aboard the SS City of Benares to safety in Canada. Life aboard the luxury ship is grand - nine-course meals, new friends, and a life far from the bombs, rations, and his stepmum's glare. Finallly, on the fifth day at sea,...