History's Greatest Mysteries Season 6: Episode Guide & Ratings

It's one of America's most mythic UFO incidents. A 200 yard swath of debris that landed near Roswell, New Mexico. Some believe it was an alien craft, others that it was a secret government experiment. The deeper researchers dig, the more perplexing the story gets. It's a mystery that's endured for nearly 80 years. So what really crashed in Roswell in 1947?

The search for the illusive Northwest Passage, leads to a historic expedition that sets sail into a labyrinth of ice and is never heard from again. That disappearance sparks a search for clues spanning nearly two centuries and leads to unthinkable ends. What really killed the men of the Franklin Expedition?

On February 14th 1929, one of the most shocking murders in mob history goes down in Chicago and becomes known as the Valentine's Day Massacre. The 20s and 30s are full of gangland murders, but the Valentine's Day Massacre is considered the most brutal and the toughest to solve. So who carried out the Valentine's Day Massacre and why?

Sightings of the Yeti, a creature of myth and legend, have been recorded for thousands of years throughout the Himalayas and surrounding regions. Could this seven foot tall creature, covered in shaggy gray hair, be hiding in plain sight? And if the Yeti does exist, is it a living being or something else entirely?

Amelia Earhart, the world's most famous female pilot, takes off on the final leg of a record breaking flight. But Earhart never arrives at her next stop, a tiny island in the Pacific Ocean. The search for this famed flier has revealed conflicting stories and in the eyes of some, secrecy. What really happened to Amelia and her navigator?

Pablo Escobar, the notorious narco trafficker who single handedly supplied most of America's cocaine in the 1980s, had billions of dollars in cash and hid stacks of it all over the country. By the time he was gunned down in 1993, it's believed he was worth over $50 billion in today's money. To some, he was a Robin Hood. To others, he was pure evil. Who killed Pablo Escobar and where did all his money go?

Cash, jewels and two million dollars in gold bars. Jesse James and his gang robbed trains, stagecoaches and banks They buried the spoils, but only a fraction of the millions has actually been found. If James and his gang hid a fortune, where could it be?

A surreal event outside a U.S. Air Force base near the Rendlesham Forest in England, becomes an international legend and one of history's strangest unidentified encounters. For more than 40 years, the question has endured... What was really out there in the Rendlesham Forest and what were the Rendlesham lights?

The legendary ancient ruler, who amassed a fortune estimated to be worth 120 trillion in today's dollars, Genghis Khan hid his riches so well that to this day, no one has unearthed them. 800 years later, the fate of his treasure remains a mystery. Where are Genghis Khan's buried riches?