Lee Tergesen, Eloise Mumford and Leslie Hope

Sixteen days down the Boiuna, and the determined folks looking for Dr. Emmet Cole in the Amazon have already been assaulted by cockroach storms, the creepy dolls of a dead girl, el corpo seco, spontaneous blindness, and a hanging man who can't die.

But the really freaky stuff isn't going to come from outside of the Magus for much longer.

"It's not just scares that jump out of trees from here on out," Leslie Hope, who plays The River's Tess Cole, tells TVGuide.com. "As this group of people get more and more wrought and paranoid and tense and exhausted, more and more things happen between the characters that are as mysterious and scary as what's happening out in the jungle."

Bruce Greenwood: ABC's The River is more than just a horror story

In other words, they're all about to lose their minds, secret agendas are about to explode, and people will die. Hopefully just in time, too. The show's two-hour premiere was watched by 7.6 million viewers earlier this month, but just 4.8 million watched the most recent fourth hour. "It's a big swing — we're definitely in the go big or go home category," Hope says. She and River executive producers Michael Green and Zach Estrin agreed to divulge a few of the ways things are about to get mind-boggling as we head into the first season's final four hours.

Lincoln's about to get flip-turned upside down. Literally? Maybe! The group's science guy and resident cynic will go through something extreme in the finale. "Wait until you see where Lincoln (Joe Anderson) goes," Green says. "Let's just say there are some absolutely terrifying things that come out of him." Teases Estrin: "It's very, very physical. His body will do things you won't believe." CGI not necessary.

Check out photos from The River

People will die. Don't rule out anyone. But also, being dead doesn't mean you're dead dead. It doesn't mean you disappear off the show.

The "source" will be revealed. Why was Emmet (Bruce Greenwood) after this source? "For us to understand it, the source is the source of all things, all life, all power, all good, all evil," Hope says. Uh oh, playing God, Emmet? The consequences sound not good. "As we get closer to him and by definition closer to the source, the rules start to break down. The more important question is: What has he been doing on the other side?" Other side?!

No turning back now. Even if the crew decided they'd had enough of the Amazon's most hostile and haunted spirits, they can't go back. Hope says it's impossible. "They can't turn around," she says, and that isn't so great for the crew because finding Emmet is less and less of an incentive for everyone who isn't Tess. "She becomes isolated in her determination to find him. Driving the ship forward becomes more of a lonely enterprise as her support kind of drops away." Jeez, who are these people she's surrounded by? What do they all really want?

Expect resolution at the end of this eight-episode season. But does resolution mean they'll find Emmet? (Hmm, next week's episode, airing March 6, is called "Dr. Emmet Cole.") Rest assured there will be resolution on this journey. But there's a twist! "Whatever we find should not be taken at face value," Hope says. "There's definitely discovery, but it's not what you think. It will be in front of your very eyes, and then rules will bend again."

Hey ABC, how's that renewal looking? 

The River airs Tuesdays at 9/8c on ABC. Any theories as to what's up with Emmet, who we last saw possess the bodies of our fine crew? Are any of them in cahoots with him? What do you think will happen to Lincoln in the finale? Best guesses go below, please.