The dam keeper

"In less than twenty-four hours, the poisonous tidal wave of black fog will descend on Pig's home. While Fox, Hippo, and Van hurry eat to warn the townspeople, Pig ventures on his own path. Pig is following a trail of clues that are inexplicably linked to his father, and now that trail is leading upward. What he finds on a floating island above the clouds will shake him to his core, but it just might be the answer he needs to save Sunrise Valley"--Dust jacket flap.