Kari & Tory conduct a battle of the sexes to determine which gender handles the rush of extreme thrills better. They will test groups of men and women on the launch coaster Thunderbird - going upside-down through 160-ft loop.

Tory experiments with Kari senses as she rides Colorado's Glenwood Canyon Flyer ride, which swings riders over a 1,300-foot cliff. She'll be vision and hearing deprived, testing how sight and sounds add to the thrills of a ride.

Tory and Kari use accelerometers and state-of-the-art eye-tracking equipment to determine the best place seat on a roller coaster. Their laboratory is Hades 360 in Wisconsin, the only wooden coaster that has a corkscrew.

Tory and Kari are on a scientific quest to find out if there really is such a thing as an adrenaline junkie.

Tory and Kari step aboard an epic coaster at Six Flags Magic Mountain in Valencia, California called Apocalypse to see what physiological effects thrill rides have on the body.

Tory & Kari set up shop trackside at Sonoma Raceway in Sonoma, CA, where Tory enrolls in racing school at Simraceway Performance Driving Center.

Kari heads to Wet 'N' Wild in Palm Springs, CA to learn the science behind waterslides.

Kari & Tory climb aboard specially outfitted acrobatic aircrafts to test how intense g force conditions affect a person's body and mind.

Kari & Tory ride down a bobsled 60 mph around dangerous curves at Lake Placid, NY, a training ground for Olympian bobsled riders. However, will the thrill of the bobsled match that of the traditional roller coaster ride?

Kari & Tory travel across the US, exploring the fun of fear as they enter two of the country's most notorious haunted houses. Along the way, they examine the science behind some of the country's most epic fall traditions.