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.

A fugitive, an empty house, a rotting corpse. The journey begins. Cameron Matthews, a petty criminal and fugitive from the law, hides from police by taking shelter in an old dilapidated house in the middle of the city. There he discovers the rotting corpse of Bart Giordano, the owner of the house, whose death has gone unnoticed by friends and family for years. Though separated by death, the two men form an unlikely spiritual connection and help each other rebuild broken relationships in their personal lives.

In 2009, the small town of Cohasset, Massachusetts was rocked with tragedy. A 17-year-old high school senior named Collin Mason murdered three classmates. All the murders were videotaped and uploaded to the Internet via bit torrent sites and for three days, the world viewed the murders of these three innocent teens. Through legal action, the parents of the victims were able to remove all footage from the Internet and the town tried to save face by pretending it never happened. Bootleg copies of this footage are still passed around and downloaded through illegal means. The impact of this video is still being felt in Cohasset today. The video has become infamous, and is now referred to as The Cohasset Snuff Film.