Daniel Arnold, a professional photographer who, with his wife Becky, has just moved into his ancestral home, buys an old trunk at an estate sale of a famous local adventurer. The trunk has a false bottom, where he finds an old camera hidden, a Kodak 100. The camera still has film in it; film with 70-year-old+ pictures on it. Becky asks him to fix her little pocket Instamatic camera; the door that holds the film in won't stay shut. He says he will, and she leaves it by the kitchen door. He forgets about fixing the camera. It takes him many hours to develop the film from the old camera. The pictures that emerge are exciting; one of them states it was a National Geographic expedition to the Amazon river basin in 1913. The pictures show men and women dressed in turn-of-the-century clothes, with Amazonian natives in their village, dressed in traditional garb.

Daniel remembers that one of the town's oldest men, now a professor, went on the trip as a boy, and he drives over to talk with him. Becky hears a few odd sounds as he leaves. She takes the knife she'd been chopping vegetables with into the living room, looking for the cause of the sounds. She walks past the parlor, and we hear a scream.

Cut to Daniel and the professor talking about the expedition. The professor talks about the tribe, the Curacai, and how eerie it sounded when they were on the hunt. They used a high whistling sound that grated on your nerves. The photographer shows him the pictures, but the old man says there can be no pictures of the Curacai. They believed that to take a picture of them meant you stole their soul, and they nearly killed the foreigners when anyone attempted to take their pictures. The expedition ran into the jungle to get away, all the while the Curacai whistling sounds echoed around them. The photographer disappeared that night. Daniel says that the photographer must have taken the pictures, because the natives were on the film. But when the professor looks through the photos, the natives are gone. The people from the expedition are on the film, but not the natives. Suddenly, Daniel's scared.

He hurries back home, only to find the house apparently deserted. He walks through the kitchen, then through the parlor. There are jungle noises, and a bird flies through the room. He calls for his wife, but no answer. There is movement in the plants, and when he goes over to look, he sees one of the Amazonian natives crouching behind it! He falls back onto a couch, startled, but yells out. The natives have boobytrapped the couch (and the rest of the house) by sticking forks through the seat, and one of the forks pierced his arm. He pulls it out and hearing Becky screaming up stairs he runs up, stumbling on a wire pulled across the top stair and falling on broken glass. He finds Becky in a closet, tied up, and one of the natives falls on him. They fight, and he grabs a camera to use as a weapon. In reaction he hits the button on the camera. The indian changes to a negative image for a second then vanishes, his spirit captured back on film.

He unties Becky and tries to get her out, but another native jumps out at them. He uses the camera on him, and two others setting up a bow and arrow trap in a bedroom. As they get downstairs, 3 more run at them and Daniel captures them all on film. On the porch, another one begins fighting with Daniel, but he's out of film. Becky remembers her broken Instamatic, and after a few agonizing moments of fumbling with the broken catch, she manages to get the camera to work long enough to take the last native's picture.

"Ancient maps included unknown lands labeled "Terra Incognita," and warnings like "Here there by Tygers." Modern maps of an enlightened world show no such disclaimers. Perhaps they should. Perhaps even today there are realms which cannot be charted anywhere, outside the Twilight Zone."