March 1865. A group of Union soldiers escape from Confederate hands in a balloon, accompanied by their former Confederate captor. The balloon crashes on a sinister island where they encounter all manner of oddities and dangers.

Corrupt officers track men for sport with dogs.

When Jimmy's father gets a promotion, the family must relocate to an apartment in New York City that has a strict "no pet" policy. Unwilling to let his master go without a fight, Rainy embarks on a cross-country journey to New York.