Accidentally freed from 5000 year long imprisonment, a band of Demons, led by a creature named Diabolico, return to the city of Mariner Bay, built upon the ground they once called their homeland. They seek to revive their ruler, Queen Bansheera, and plot wipe out the humans to reclaim their rightful property. Prepared for their return, a secret government agency known as Lightspeed recruits a team of five young adults, each an expert in a specific field (a firefighter, a stunt pilot, an extreme sports enthusiast, a diver, and a nurse in training), to become the team of Power Rangers to rescue Mariner Bay from this menace.