The CDC, the U.S. Army and a Bronx Zoo veterinarian join forces to identify the disease rapidly filling the city's emergency rooms and curiously killing 17,000 crows and zoo birds in NYC. Then, an unidentified virus tears through the Southwest.

Recipients of a single organ donor exhibit the same bizarre, manic behavior before lapsing into comas. Then, in the Midwest, a mysterious and terrifying pox outbreak has left more than 70 patients plagued by strange, pus-filled lesions.

Violent flu-like symptoms strike down men in the college town of Fort Collins, Colorado. Then, an elderly woman who just returned from China is rushed to a Northern Virginia hospital. Has this woman brought a terrifying disease to US soil?

Hundreds of injured soldiers returning from the Middle East bring back incredibly powerful mutant bacteria. Also, the CDC is flooded with reports of severe illness in children across the country - an invisible assassin is on nationwide killing spree.

After a huge earthquake hits California, a deadly fever is spreading quickly, and it's likely caused by a fungus released by the quake. Then in another story, a horrendous bacterial outbreak forces one of the largest food recalls in U.S. history.

Bobo, Cliff, Matt and Ranae travel to the forests of northern Georgia to examine footage of what could be a Bigfoot running across the road.

The team heads to northern Florida to help a family that believes they have a Bigfoot living on their property, then they meet with members of the Seminole nation, whose history with the creature goes back hundreds of years.

From deep inside the NC Uhwarrie National forest comes one of the most convincing pieces of Bigfoot footage from the past 40 years. Investigators use decades worth of experiences to determine if this footage is the real deal.

The specialists head to Oregon to examine a video taken on a rafting expedition. While investigating, the team hears a sound in the middle of the night that they believe could prove the creature's existence.

The investigators journey into the mountains of southern Washington to explore a series of photos that depict what some believe is a Bigfoot on a snowy peak.

A call from a concerned mayor brings the team of experts to the island of Prince of Wales, Alaska. The island has a long history with the beast, but a recent spike in activity has the townspeople on edge.

Bobo, Cliff, Matt and Ranae return to Oregon to participate in their favorite event, Bigfoot and Beer. The team reflects on their expeditions, answers questions and shares some never-before-seen moments.

The team heads to New York to investigate video of an alleged baby Bigfoot. When locals report activity in the neighboring woods, the team tries a new search method in hopes of finding Bigfoots near the Big Apple.

The investigators go to Rhode Island to examine video of a roadside sighting of a Bigfoot. They learn that this unexplored area has a wealth of Sasquatch activity and hope to prove that this small state is hiding Bigfoots.

The team heads to Minnesota to investigate intriguing howls recorded at an infamous Bigfoot hot spot. They go deep into the wild, hot on the trail of Bigfoots rumored to be bigger and bolder than any other on earth.

The team travels to Canada to investigate a unique Bigfoot encounter caught on tape. The team zeroes in on the Canadian Rockies in search of what may be the most territorial Sasquatches on earth.