Built over 200 years ago in a small Wampanoag community at the tip of an island in the Atlantic, the Gay Head Lighthouse is one of America's most famous beacons. From whaling days to electrification, 'Keepers of the Light' tells the story of evolving technology, heroism and shipwrecks, and the people who are called upon in each generation to keep the light, woven with the story of the recent race against time to save the historic beacon from falling over the edge of the rapidly eroding cliffs.