On legendary Easter Island, a team of National Geographic explorers and scientists undertakes a groundbreaking expedition: to attempt a first-ever mapping of the vast cave system beneath this enigmatic isle. We ride along as the team rappels down sheer cliffs, crawls through narrow labyrinths, and even dons SCUBA gear to complete their task. Deep beneath the earth, in caverns that have been forgotten for centuries, these adventurers discover human remains and telltale artifacts. Together, these finds reveal an astonishing history that is brought to life in startling re-enactments. It is a tale of ingenious achievement, environmental catastrophe, and brutal social breakdown one that remains a haunting lesson for all of us, similarly trapped on an island planet of our own.