Stalked by the deadliest animals including lions, spitting cobras and bull sharks, survivalists' every step could bring disaster. To make it 40 Days, they must use their skills to avoid becoming prey while hunting the most dangerous creatures.

Season Finale. Medics closely monitor Jeff's high fever and prepare his evacuation. The others scramble for a 5-mile extraction journey through shark-infested waters. A survivalist pushes too hard leading to a medical emergency on the open sea.

Jeff is called out for his "no hand-outs" survival strategy but refuses to back down. Through a free-wheeling discussion, new interviews, and never-before-seen footage, it's a new look into how the survivalists survived land, sea and each other.

Rescuing stranded climbers with no coordinates is a daunting task.

Jason preps his helicopter for the world's highest landing spot.

Ryan battles the elements racing back to Lukla with sick climbers.

Ryan confronts an uninvited climber trying to hitch a ride at 17,500 feet.

Jason and Siddartha try to save climbers along a treacherous icefall.

Ryan struggles to locate a woman suffering from severe abdominal pains.

Jason Staker builds a shelter capable of protecting against large wild animals and standing up against the elements in the Aspen Grove forest.

T.J. builds a 5-foot elevated tree house capable of keeping his team safe from flash floods in the High Mountain Valley.

Cat builds a 10-foot elevated tree house capable of keeping her team safe from flash floods in the High Mountain Valley.

Joel builds a watercraft capable of carrying his team and supplies across the Alpine Lake.

Tamra builds a shelter capable of keeping her team safe during the heavy rainfalls present in the Spruce Forest, as well as a bridge to grant access across a crucial stream running through the forest.

Matt builds a seasonal hunting camp in the Chalk Creek hunting grounds.

Stranded deep in the Amazon, Mykel and Ruth fight to survive the searing heat, poisonous reptiles, and a jungle that conceals its most deadly threats - and the way out.