Prepare to expand your definition of what a cave is when we sink into the dark, moist abscesses of the earth. We keep it in the states this episode as first Danielle carefully creeps us around the lush bounty of the Ozarks to find the cool, moist, Grotto Salamander, then we switch gears dramatically as Katie walks us deep into the desert only to find solace in the hot tub temperature waters that make the sanctuary of the Devil's Hole Pupfish. 
Gather your headlamps, water shoes and... SCUBA gear, we're going caving!