This sequel continues the plight of Jacob and his new friends where the first book ended. Having escaped their island home by the skin of their teeth, the peculiars must journey to 1940 London, the central city of the peculiar underworld. They find new allies and a menagerie of peculiar animals along the way—while avoiding the wights and their hollowgasts— in hopes of finding the way to return Miss Peregrine to human form.