Know to be man's best friends, cats and dogs have engaged in a fierce and merciless battle. Now, Mr. Tinkles, a ruthless cat, is plotting intensively to achieve nothing less than world domination. His main target is Professor Brody. The professor is working on a medication that will rid people of their dog hair allergies. Mr. Tinkles strives to get to the substance and have it analyzed. He then means to have it altered so that all humans of the world...

The crew continues their thrilling and terrifying tour of the Most Hauntedest Place on Earth! In these final episodes of Season 2, the Mystery Inc. crew races against time, creepy creatures, and other interested parties to solve long-buried secrets of their hometown. Can the gang also solve their greatest mystery yet and save Earth from destruction?