"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.