In the summer of 1952, Betsy sees her vacation fun overshadowed by the spreading polio epidemic, while her mother and other scientists work frantically to develop a vaccine for the crippling disease.

Ten-year-old Little Joey Norman, a hot new star in the silent films of Hollywood, wonders if he can make the transition to the talkies when sound is introduced to the movies.

Shy, bookish Jane is both intrigued and suspicious about the charming but mysterious Peter Joyce until he and ten other kids disappear from the beach one night, in a fantastical undersea adventure.