Blackwater Ridge, Lost Creek, Colorado
Inside of a tent, two college-age boys, Brad and Gary, are playing handheld video games while a creature lurks outside. In the other tent, the third camper, Tommy Collins, uses his handheld camcorder to record a message to his sister Haley back home. Brad goes out relieve himself next to a tree. He starts hearing rustling noises and notices branches moving. The boys back at camp hear Brad screaming and start calling out to their friend. The creature rips through the tent and grabs Gary, and then goes after Tommy.
Palo Alto, California
Sam carries a bouquet of flowers to Jessica’s grave. He begins to tell her that he should have protected her and how he should have told her the truth. As he leans down to place the flowers on her grave, a dirty hand shoots through the dirt and grabs on to Sam’s arm.
Outside Grand Junction, Colorado
Sam jolts awake from his nightmare and finds himself in the passenger seat of the Impala. Dean looks over and asks if he had another nightmare, then asks if he wants to drive. Shocked, Sam points out that Dean has never offered to let him drive, and insists that he's fine. However, Dean doesn’t buy it, but Sam tries to change the subject by pulling out a map and asking where they are. Dean tells him that they’re outside of Grand Junction, Colorado. Sam tells Dean how he regrets leaving Palo Alto so soon after Jessica’s death. Dean says that they spent a week looking for clues without success, and to find Jessica's killer, they'll have to find their father. Sam looks down at the map and says that the coordinates their father gave them are strange because they point to Blackwater Ridge and there’s nothing there except woods.
Inside the visitor’s center, Sam looks at a map of Blackwater Ridge and confirms how remote it is. Dean stares at a photo on the wall of a large bear. A ranger, Wilkinson, asks why they're there. When they claim that they're Environmental Study Majors from UC Boulder, Wilkinson figures that they're lying and says that they're friends of Haley Collins, who filed a missing-persons report. He tells the brothers that Tommy filed a backcountry permit and isn't due back yet. Dean plays along and asks to see the permit so he can reassure Haley. Outside, Sam wonders why they're wasting time talking to Haley, and wonders if Dean is trying to pick up a girl. He wonders why Sam is suddenly so eager to leap in without checking things out, and Sam says that he is now.
Sam and Dean go to see Haley, pretending to be park rangers. She lets them in and ask why she thinks something is wrong with Tommy, and Haley explains that her brother checked in every day with his satellite phone. She hasn’t heard from him in three days. When Dean suggests that Tommy forgot to check in, Haley's younger brother Ben says that Tommy wouldn’t do that, because they all keep close tabs on each other now that their parents are dead. She shows them the pictures and video that Tommy sent, and Sam notices something in the background of the last video. Dean tells Haley that they’re going to head over to Blackwater Ridge to check up on her brother, but Haley says that she's hired a guide and is going to check it out herself. Sam asks her to forward the photos and video to him and Haley agrees.
At a smoke-filled bar, Sam tells Dean that despite the low traffic at Blackwater Ridge, two hikers recently went missing. Sam pulls out copies of old newspaper clippings that show that there has been a “grizzly attack” every 23 years: one in 1936, 1959, and 1982. He plays Tommy’s video for Dean and pauses it to show a shadowy figure moving at high speed outside of the tent behind Tommy. Dean happily tells Sam that he knew something weird was going on, and Sam confirms that someone survived the attack in 1959.
Sam and Dean pose as park rangers again and talk to the survivor, Mr. Shaw. Shaw tells the brothers that a grizzly bear attacked them, but Dean, believing that the man is lying, pushes him for answers. The old man tells them that he knows they wouldn’t believe him if he told them. Sam asks Shaw what he saw, and the survivor tells them about the creature--fast-moving with a roar unlike anything he’d ever heard before. He tells them how the creature was able to unlock the door and get into their cabin. Shaw loosens his collar and shows Sam and Dean his scars: three long cuts from his collarbone to his chest. He then tells them that “there’s something evil in those woods, some sort of spirit or demon.
Back at the motel, Dean and Sam talk about their interview with Shaw. They discuss about how demons and ghosts don’t need to unlock doors to get inside; they just go through walls. Sam asks Dean what he thinks it is, and Dean figures that they can kill it without supernatural gear. As Dean starts picking out guns, Sam says that they need to stop Haley before she goes up alone against the creature to save Tommy. Dean figures that Haley isn't going to stop because they tell her a story about a mystical monster, and argues that they need to go with her to keep her safe. Sam, angry, complains about how it’s not enough that they have to find Dad, now they have to babysit a stranger. Disgusted, Sam throws the bag of guns at Dean and walks away.
Near Blackwater Ridge, Roy, Haley's guide, loads up a gun while telling Haley that Ben shouldn’t have come. Sam and Dean pull up alongside of them and ask if they have room for them. Haley tells Roy that that the two are rangers, and all that the park service would send. She notes that they're not dressed for hiking, but Dean insists he doesn't do shorts. Roy warns them that Tommy could be hurt, and it's dangerous back country.
Inside of a cave, Tommy and Gary are hung up by their arms. The creature approaches them and advances on Gary.
Dean, Sam, Haley, Roy, and Ben hike through the wilderness. Dean asks Roy about his hunting and what he typically hunts, and asks if anything ever hunted him back. Roy responds by grabbing Dean's arm and stops him from stepping onto a bear trap. Haley hurries to catch up to Dean and starts asking about him and his brother, figuring they're not equipped as rangers. Dean says that they're also looking for their father, and Haley tells him that she understands.
The group approaches Blackwater Ridge. Dean and Sam notice that it’s too quiet outside--not even crickets are chirping. The coordinates match those that John sent them. Ray finds the trashed campsite and calls the others, and they realize the tents are shredded and covered in blood. Haley starts screaming and searching the campsite for any sign of Tommy or the others. Sam hurries to her side and tells her she has to be quiet in case something is still out there. Dean calls Sam over to show him that the bodies were dragged from the campsite and points to a trail of blood leading away from the tents. Haley finds Tommy’s video camera in the mud as a man’s voice yells for help in the distance. The group rushes back up the trail toward the sound of the voice but find nothing. Sam orders everyone back to camp, and they find that their packs have been stolen.
Sam pulls Dean aside to talk in private. They pull out their father’s journal and flip to a page with a creature drawn on it. Dean tells Sam that it couldn’t be a Wendigo; they live in northern Minnesota. Sam explains that all the evidence point to a Wendigo. Sam walks back to the group and tells them that they have to get going. Roy and Sam argue about whether Roy can handle the creature, and Haley finally splits them up. She refuses to leave without Tommy. Dean tells the group that it’s getting too dark and they won’t be able to fight the creature in the dark, so they need to find a safe place to stay for the night.
As the sun goes down, Dean traces designs into the dirt and explains to Haley that they’re Anasazi symbols that Wendigos won’t cross. Dean leaves the campsite to check on Sam. Sam begins to question their purpose and why they’re wasting time fighting creatures in the woods, now that they know that John isn't there. Dean pulls out their father’s journal and tells his brother that he thinks their father wants his sons to take up where he left off. He explains how their father passed down the family business and now it’s their turn to save people. Sam tells his brother that he needs to get out of here to find his father and Jessica’s killer, and Dean promises that they'll find John, but it will take a while. Sam has to have patience, and Sam wonders how Dean and John do it.
The same voice yells for help. The group looks out into the forest as Dean tells them to stay put. The yelling continues, as does the sound of growling circling around them. Roy begins to shoot into the woods until he hears a yelp. Thinking he hit whatever the creature was, Roy runs into the forest. Sam and Dean run after him, and Roy pauses when he hears a voice yell. The Wendigo reaches down, grabs Roy, and snaps his neck.
The next morning, Haley asks Dean how he knows about “this stuff”, and Dean tells her that it runs in the family. Sam approaches the group, and with Dean’s help, explains about the Wendigo. Wendigo are outdoorsmen transformed into inhuman creatures when they resorted to cannibalism. Haley asks how can Tommy still be alive, and Dean tells her that Wendigos hibernate for years at a time and store their victims so it can feed whenever they want. The only way to kill it is to burn it.
Sam leads the group after the Wendigo by following bloody claw marks on the trees. He finally realizes that the marks are too easy to follow and that they’ve been led. The Wendigo starts growling and circling the group, and blood drips on Haley’s shoulder. She dives out of the way as a body plummets down from the trees: Roy. They run away and Ben falls. Sam runs back to pick up Ben. By the time that they catch up to Haley and Dean, they’ve disappeared. Sam yells for Dean, but gets no response.
Ben and Sam travel together through the forest. Ben asks why the Wendigo wanted to kill Roy, and Sam tells him that the Wendigo was probably pissed that he shot at him. Ben finds a trail of M&Ms on the ground, and he and Sam follow the trail to an abandoned mine. In the mine, they hear growling and step forward onto a floor board that gives way. They fall onto a floor beneath that’s covered in human skulls. Sam tries to keep Ben calm, but has a hard time doing so when they see Dean and Haley hanging from the ceiling. Sam and Ben help them down and then find Tommy and help him down. Dean finds flare guns in the corner as the Wendigo returns. Dean tells Sam to get Haley and her family out of the mine.
Dean begins to yell at the Wendigo, while Sam gets the Collins out. Sam turns to see the Wendigo behind him and shoots at it. He misses as the creatures ducks out of the way, and runs to the Collins. As the creatures closes in on them, they come to a dead end. Dean hears the noise at the other end of the mine and begins to head towards it. The Wendigo creeps up on Sam, Haley, Tommy, and Ben just as Dean rushes up behind it and shoots it. The flare embeds itself in its torso and consumes it from within.
Back at the visitor center, Sam and Ben tell the police that they were attacked by a grizzly bear. Haley tells Dean she doesn’t know how to thank him, and he, in turn, gives her a suggestive smile. She kisses him on the check and says she hopes he finds his father, and then gets into the ambulance with her brother. Dean tells Sam that they’ll find John, and Sam agrees... and says from now on, he's driving.