The product line focuses on the Dr. Rodney Rathbone finds out that Lord Vampyre, the ruler of the Monster Realm, wants to turn day into night forever and unleash his army of monsters into the world of mortal minifigures. To accomplish his plan, Lord Vampyre must gather six magic moonstones and use them in a machine of his own creation, which can direct the magic of the gems and begin an eternal eclipse of the Sun. He and his team of Monster Fighters embark on a mission to prevent the monsters from completing their evil plot.