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.

An IMAX filmmaker and an atmospheric scientist try to intercept tornadoes.

A chase is cut short when the storm moves into an area without paved roads.

Sean begins to trust his instincts over Josh's science.

Tornado season winds down, and Sean seeks a shot from inside a vortex.

Storm season starts out deadly, and Josh and Sean race to get a bigger, badder Tornado Intercept Vehicle, TIV-2, on the road. Meanwhile, a new force of nature emerges in Tornado Alley as Reed Timmer beats the pros to get tornado intercepts.

Sean's new TIV-2 loses parts, and Reed's team pursues a storm in Texas.

Tensions mount between Sean and Josh, and Reed chases a nighttime tornado.

A monster EF-4 tornado chases the storm chasers through eastern Arkansas.

Josh tries to fix broken radar, and a team tries to escape a ditch.

The storm chasers mobilize as tornadoes form all over western Kansas.