Secrets at Sea follows a family of mice as they follow their humans to Europe on an ocean liner. The story is narrated by the oldest sister, Helena, and set in the Victorian era. The narration is very clever and humorous, of course, since the author is Richard Peck. The only only thing I can see someone objecting to is that the purpose of the humans' trip to Europe is to "marry off" the oldest, rather plain looking daughter. And the three female mice are a bit stereotypical (oldest is responsible one, the other two are mouse-man crazy - possibly historically accurate given women's limited choices back then, but still).