A beautiful native guide splits the loyalties of two guides seeking the sky burial platforms from the Orphan Tsunami of 1700. But they found too late that she will never let them leave the forest alive.

What if an extra-terrestrial force attacked Earth? What might that look like and how will the people of Earth respond? Consulting a cast of world-renowned scientists, survival experts and defense experts, National Geographic explores this frightening scenario. Experts reveal what could motivate alien invaders to attack Earth, and speculate on how the attack might play out, the strategy alien invaders might use, and the most effective ways for humans to respond.