Things kicked off to a rocky start when the Pretty Woman star and the survival expert flew into Kenya and endured something of a rough landing that had Roberts screaming the entire time.
However, that wasn't nearly as nerve-wracking as what happened when Roberts and Grylls had to get across a gorge on a rickety bridge hanging above a dangerous river filled with hungry crocodiles.
"We’ve come to a bridge that crosses a river full of crocs," Roberts explained to the cameras. "I'm just [dripping] with sweat due to nerves. I'm very afraid of heights and I always have been."
As Roberts was buckled into her harness -- which would hopefully keep her safe in the event of a bridge collapse -- the actress joked with Grylls, "Can't this episode just be running slightly less wild?"
While the crossing was frightening -- thanks to a stubborn croc that kept popping up above the waterline right below their feet -- the twosome eventually made it across unscathed.
"I don't know if we're gonna be best friends now, or if this is the end for us," Roberts told Grylls as she tried to catch her breath.
Later, Grylls put the Oscar winner's gag reflex to the test by cooking a goat over a fire, chopping open it's skull and chowing down on a bit of it's brain.
"Do you think it will make me smarter if I eat it?" Roberts asked, nervously, as she considered whether not to eat the dubious meal. "[Bear], I have so much conflict about how I feel about you."
Check out the video below to see how Dancing With the Stars judge Julianne Hough fared when she faced the harsh wilderness with Grylls on an epic past episode of Running Wild.