Quagmire

In blue ridge, Georgia, biologist Paul Farraday and Federal inspector William Bailey argue on the lake shore about a dwindling population of frogs. An angry Farraday leaves, while Bailey goes to find the lost pager, but is attacked by an unknown creature that drags him under the water.

Mulder and Scully, picked up in a hurry and forced to take their Spitz Queequeg with them, go to investigate Bailey's disappearance. Mulder informs Scully of the boy scout leader's disappearance at the same lake a few days earlier. After getting lost, the agents stop by a local store called "Ted's", which sells, among other things, goods that exploit interest in the mysterious monster Big Blue Snake. At this time, a local fisherman accidentally pulls the half-eaten body of the missing boy scout leader out of the lake.

Late in the evening, Ted, the owner of the store, leaves tracks on the shore that mimic the tracks of a monster, but is attacked by an unknown animal and dies. Mulder wants to close the lake to the public, but comes across the refusal of the Sheriff, who does not believe in the existence of a monster. In parallel, two teenagers (who previously appeared in the episode" war of the coprophages") on the pier are trying to achieve drug intoxication by licking the backs of frogs, when their friend, who is swimming in a lake with scuba gear, is attacked by an unknown creature and his head is torn off. Scully does not believe in the existence of a monster, believing that the diver cut off the head of the propeller of a motor boat. The next victim of an unknown animal is the photographer Ansel, who before his death manages to take several pictures, the contents of which cannot be distinguished. Late in the evening, Scully goes to walk Queequeg; the dog runs off into the woods, where it falls victim to an unknown animal. Mulder deduces that the creature migrated closer to the shore.

The agents rent a boat, but crash-land, had sprung up on the rocks. Unable to see anything in the dark, they decide to wait out the night on the rocks. As it turns out later, they are very close to the shore, and the sound of their voices attracts the attention of Dr. Farraday. Mulder puts forward the theory that the lake monster caused the death of frogs, but because of the reduction in their population, he was forced to look for a source of food closer to the shore. After a while, Farraday becomes the victim of the attack, but he survives. Mulder rushes into the woods, and soon manages to shoot the animal, which turns out to be a large alligator.

As the agents leave blue ridge, a plesiosaur-like creature emerges from the lake and, unnoticed, disappears into the water.