A day for celebrating Hal and his favorite chew toy Mr. Chewinsky's three-year anniversary as dog and toy has gone from joyous fun to total sadness as Nature Cat has made a terrible mistake! Nature Cat accidentally dropped Mr. Chewinsky down the storm drain, and now he is floating on the storm water, working his way through the drain system to the river and out to the ocean! Oh no! As the gang goes to find and save Mr. Chewinsky, they learn how all waterways are connected, and also meet up with a... [see more] new special friend named Nature Dog, who helps them navigate the oceans. Will they find Mr. Chewinsky? Will Hal be able to celebrate his anniversary!? And who is Nature Dog?!