The show was set in Beverly Hills, California. The four central characters of the show were teens selected by a alien named Nimbar to fight off the monsters sent by the evil Emperor Gorganus. Gorganus is intent on conquering Earth because it is the focal point for a network of "Power Portals" that would facilitate conquest of the galaxy. In the first episode, Nimbar recruits the four high school students and with a touch by his slimy "finger" gives them each a special tattoo based on a constellation in the celestial sphere. When their tattoos flash, this means Nimbar needs them and a portal appears that they can pass through to enter his chamber. Nimbar is the Head Protector of the Power Portals. As such, he served as a Zordon-style mentor.