Lincoln comes in to see Clark, who has a lead on Emmet. He's found a cave on a lot of Emmet's tapes, and Lena pinpoints a location from the rock color. Lincoln warns that it's in hostile territory but Tess insists on going and tells everyone to pack. Meanwhile, Kurt says that he's only there because he's being paid. Emilio says that he's there because Emmet gave him a home and he owes him.
Day 12: Tires Region, Amazon.
The crew makes their way through the jungle, and Tess insists on continuing even as night approaches. They find a cave formation similar to one on the videos, and markings that belong to the local "Guardians of the Forest," the Morcegos.
AJ talks about how he was caught in a cave-in.
AJ refuses to go into the cave and gives the video camera to Emilio. The rest of the group goes into the cave and find a corpse. There is a piece of paper on it and they use it to confirm that it is a Peace Corp missionary, and he has been disemboweled. Jahel says that it's the Morcegos.
Outside, AJ sets up the mounted camera.
The group continues exploring the cave and hears bats. They find a cavern filled with the creatures, which swarm when they turn up the lights. Everyone runs out and regroups, and AJ laughs, noting that they're all covered in guano.
That night, an angry Kurt throws AJ's sleeping bag into the jungle and tells him to find somewhere else to sleep. The others gather around the campfire and Lincoln tries to get the guano out of his hair. Lena offers to help, glad to trim his hair. As she works, she wonders if it's safe and Lincoln figures that if it was safe, they wouldn't have lost Emmet and the others.
After everyone is asleep, Morcegos tribesmen approach the camp. The next morning, AJ comes back and finds Morcegos markings all over the camp. He wakes up the others and they realize that they had visitors during the night. Jahel explains that they're on the tribe's land and the Morcegos are out there deciding if they deserve to pass. Only those worthy to see the jungle can see the jungle. Jahel realizes that her father is missing and they call for Emilio. The group finally finds him seated next to a tree. However, they soon realize that he's blind. Emilio explains that he woke in the night to urinate and his eyes gave out. Lincoln asks if he touched any plants but Emilio says that he didn't touch anything. When Lincoln suggests that they should go back, Clark insists that they should continue because the Morcegos could have killed them if they wanted them dead. As they head back for the Magus, Kurt gives Clark a gun.
AJ goes back to get one of his cameras and discovers that someone broke it. He goes after the others, who have stopped for a rest break, and complains that they're not showing him respect. A loud squealing noise echoes out of the jungle and everyone nervously looks around. Something moves in the woods and Clark opens fire. They go to investigate and discover that Clark killed a pig. Jahel warns that they were selfish for shooting something that didn't threaten them, and that they are failing the Morcegos' tests. Clark insists that they're doing nothing wrong and are only there to make a TV show, but Tess interrupts to warn the others that she's going blind.
The group gets back to the Magus and guide Emilio and Tess aboard. Kurt suggests that they isolate the afflicted but Lincoln says that it must be too late. Lena complains that her eyes are itching but insists that it's not an infection. She wonders if the powder the Morcegos used for their symbols are affecting them and goes to check Emmet's tapes.
Clark talks to Kurt privately and says that they need outside help. He tells Kurt that he knows he has a sat phone and tells him to call his friends. In response, Kurt asks if his eyes are okay.
Lincoln administers eye drops to Tess but warns that they only have enough for three people. The drops don't help and Lincoln goes to check on Emilio. Meanwhile, Jahel tries to call for help on the radio but gets no response. As she talks, she rubs at her eyes.
Clark goes over Emmet's tapes but doesn't find anything, and then he goes blind as well.
Kurt decides to take the ship away from land into the middle of the river. When he asks if Jahel has been able to raise anyone, she tells him that she's blind. Meanwhile, Tess fumbles her way through the ship, calling for Lincoln. Clark finds her and tells her that he's gone blind as well. When Tess worries that they might never see each other again, Clark assures Tess that he'd never forget her face... and then realizes that she was talking about Emmet. Tess tells her to erase the tapes of their conversation and Clark says that it wouldn't be the first time…unaware that Lincoln is nearby and has heard the whole thing.
While Jahel goes below deck, Kurt hears something outside and goes out, but finds nothing.
Lena finds one of Emmet's journals that explains that some tribes used dried ciegos seeds on darts to blind animals and make them easier to hunt. There is a bulb that grows under the Sentido tree that has a sap that will neutralize the ciegos dust. However, it grows at elevations of 750 meters, at least a half day's travel away. Lincoln figures that he and Kurt have to go before it's too late. Clark goes to get Kurt, who is still trying to spot the Morcegos while AJ films him. A severed pig head drifts across the river and Kurt draws his knife as he hears someone behind him. It's Clark, and Kurt slashes him across the stomach before he realizes who it is. Lincoln tends to his wound and manages to stabilize him, but warns that he could get worse. Lena offers to go and get the Sentido bulb while Lincoln stays to tend to Clark. Lincoln reluctantly agrees to send her with Kurt and AJ. Once they leave, one of the Morcegos boards the Magus.
In the mess room, Clark starts running a fever and Lincoln confirms that he's split his sutures. He has Jahel get some fishing line and she makes her way through the ship to where the tackle box is stored. She hears something moving but has no choice but to continue.
As Lena and the others head for the shore, AJ asks if she's okay.
Tess goes to get some clean towels and Lincoln sends Emilio with her. While he works, Lincoln asks how long Clark has been having an affair with Tess. Clark asks him what he thinks happened, and Lincoln guesses that once Emmet went missing, his mother needed someone. In response, the producer sarcastically says that Lincoln will believe what he has to believe.
Jahel goes to the wheelhouse and finds the fishing line, and then realizes that the Morcegos are there. She falls down the ladder and screams to the others, and manages to make her way to a room with Emilio and Tess, who lock their doors. Meanwhile, Lincoln locks the mess room doors.
Lena, Kurt, and AJ disembark and continue to hear the Morcegos moving around them. AJ suggests that Kurt give him the gun but the mercenary refuses. When AJ reminds him that he hasn't stabbed anyone today, Kurt knocks him to the ground. They fight briefly but then hear the Morcegos closing in. The trio runs through the jungle and Kurt fires behind them, and they finally manage to hide in the brush. The Morcegos go by, while centipedes crawl all over the group. Kurt gags Lena to keep her from calling out.
Tess warns Lincoln over the ship's phone that she can't get to him with the fishing line. Looking around the mess room, Lincoln finds a knife and prepares to cauterize Clark's wound. However, he warns that he's gone blind as well.
Once the Morcegos pass, Kurt and the others leave the brush. However, Kurt finally admits that he's been blind. Lena's eyesight is also fading and she tells AJ that he has to lead them to the Sentido tree. He tells them that he's hiking out rather than drag them along and risk his life, and walks away after telling Kurt that he could have been nicer. Kurt tells Lena that AJ isn't coming back.
Lincoln prepares to cauterize Clark's wound.
The Morcegos bang on the cabin door where Tess, Jahel, and Emilio have taken refuge. Some of them find the skylight.
Clark tells Lincoln that he deserves to know the truth, and insists that Tess didn't do anything wrong. Emmet left Tess, saying he needed to come to the Amazon one last time. Tess was done with it all and begged Emmet to stay, but he chose to go instead, saying that the expedition was too important. Emmet and Tess were separated, so her relationship with Clark wasn't cheating. When Lincoln wonders why Tess didn't tell him, Clark says that she didn't want to sully Lincoln's memory of his father. Lincoln then applies the red-hot knife.
AJ makes his way through the woods and stumbles across the Sentido tree. He sets up a camera to film himself being a hero and looks for the bulb. AJ finally finds it in a cave under a tree and realizes that he has to go underground. He starts crawling, unaware that the Morcegos are closing in. The earth starts to collapse below him but he finds the bulbs and cuts one loose.
Lincoln tells Tess that he's done what he can for Clark, and she warns her son that the Morcegos are coming back.
The earth continues to collapse around AJ.
The Morcegos yank at the skylight, and Lincoln tells Tess to find somewhere to hide. Meanwhile, Clark gets up and knocks Lincoln out, and then says that it's his turn to save the others. He yells at the Morcegos as he opens the door and stumbles out into the hallway. Tess hears him and screams at him to stop. Clark ignores her and yells that it's his fault and he's the selfish one. The Morcegos surround him and closes in.
AJ tells his father David that he loves him and he's sorry.
Clark tells the Morcegos to take him and leave the rest. They back away, leaving him alone.
At the Sentido tree, the Morcegos pull AJ out and leave him alone.
Kurt uses his sat phone to call for an extraction, making sure that Lena doesn't hear him. AJ makes his way back to his teammates.
That night, Lincoln administers the sap from the bulbs and they recover. AJ gets it on film and warns Kurt that it doesn't make them friends. Out on deck, Tess approaches her son and admits that Clark is a stupid man. Lincoln tells his mother that they'll find Emmet, but when they go home, he wants Tess to know that things don't have to go back to the way they were. He assures his mother that she can go on with her own life if she wants, and Tess says that she wants her family back and shouldn't have let things fall apart in the first place. Meanwhile, a regretful Clark watches them on the monitors. Kurt comes in to apologize for cutting him, saying that he got scared. Clark tells him to fuck off and Kurt leaves.