: The lush, oppressive greenery of the jungle acts as a character itself.
Break down the of the Colombian/Venezuelan border depicted in the show. Echo 3 s01e04
"Upriver" serves as the bridge between the "thriller" setup of the premiere and the "character study" that defines the middle of the season. It strips away the high-tech gear and leaves the protagonists with nothing but their instincts and a map of a territory that doesn't want them there. : The lush, oppressive greenery of the jungle