Ray Harmon is telling his fellow students, including an enraptured Gabe, about Redfang and how he grabbed an escaping student, Phillips, who tried to go over the wall. Ian and CJ arrive and are unimpressed.
In class, Biology tells the students that they’ll be going on a field trip into the forest to collect samples and learn more about the environment they live in. Afterward Ian and others meet in the observatory and decide to use the field trip to learn more about their surroundings so they can escape. They figure that they can split up into two teams and explore. Suki plans to identify plant specimens to place their location, and use her PDA to measure off distance. CJ has stolen acid from chem lab and plans to see if they can burn through the wall. Ian has a map and will scout for Gnome checkpoints, and then use their stolen translator to listen in on them. Gabe will photograph the wall and try to see what is beyond.
The next day, all of the students report to the cafeteria before going out into the field. However, Headmaster comes in and says that he’ll be assigning the teams. He places Ian with Cal, Gabe with Emily, Suki with Ray, and CJ with Fenton. When CJ suggests they choose their own teams, Headmaster notes that their assignment is not only to learn about their environment, but about people they normally wouldn’t associate with.
Ian figures that they can use the new assignments to their advantage by having their teammates do all the assignment work. Emily, Gabe’s student vice president, warns him that they’ll be equal out in the forest. Ray admits that he thinks Suki is cute, even though she’s disgusted by him. Fenton shows them his survival gear, including a knife. Cal tries to take it and Ian stops him. He suggests that they set aside their differences to complete the assignment, but Cal calls him “Towel Boy.” Headmaster breaks them up and suggests that they may be enemies at Tower Prep, but will need to become allies once they leave.
The field trip begins and Gabe and Emily take one direction. Gabe tries to find a tree to climb up and take photos, and Emily has no idea what he’s up to. Fenton and CJ go a different direction, and Fenton goes on and on about his experience in the woods. She finally tells him to stop acting like a Boy Scout, and Fenton shamefacedly admits that he only made it through Webelos, until he was abducted at the age of 12 and brought to Tower Prep. CJ reluctantly tells him to continue telling her what he knows about the forest.
As Ian and Cal explore, Cal lets Ian do all the work. Ian notices that Cal has food packed in his bag, and asks if he’s trying to escape. Cal ducks the question and grabs Ian’s bag, setting off the Gnome translator. Cal wonders where Ian got it, but Ian refuses to answer.
Elsewhere, Ray tries to figure out why Suki is measuring distances and ignoring their assignment. He tries to impress her, and she finally loosens up and uses her ability to impersonate Redfang. The others hear her and wonder if the real Redfang is roaming the wood. Gabe panics and trips, spraining his ankle. Emily goes to help him. Further away, Cal hears Gabe thanks to his super-hearing, but refuses to help. Ian ignores him and goes to find his friend, saying Cal is a self-centered jerk.
Ian finds Gabe and Emily, while something watches from hiding. Emily says that she’ll take Gabe back to Tower Prep and get him treatment at the infirmary. As she goes to get her equipment, Gabe admits to Ian that he failed in his assignment. Once Emily leaves with Gabe, Ian uses the translator to listen to the Gnomes, who have spotted a student approaching the wall.
Emily takes Gabe to the infirmary, where Nurse and an attractive student, Jenny, examine his ankle. Emily finds Gabe’s map and secretly pockets it.
As Ian tries to locate the Gnomes, he finds Phillips’ abandoned student uniform vest and takes it with him.
As Suki and Ray gather specimens, he complains that all she’s doing is measuring distances. She insists that it’s her methodology and goes into the brush. Ray takes a picture of her over her objections, and then informs her that she’s standing in poison ivy. Suki panics and screams, alerting Ian. As he goes to investigate, he finds a PDA on the ground.
CJ and Fenton go to the wall. While he examines animal scat, CJ starts to use her acid on the wall. However, a fly bites her and she spills the acid. Fenton notices and comes to help, and offers to suck out the poison. CJ warns him not to.
Ray uses his enhanced strength to easily carry Suki to the infirmary for treatment. He tells her that he’ll finish their assignment for both of them. As he goes, Gabe warns him that doesn’t have a chance with Suki, and Ray slaps him on the ankle.
Ian plays back the video footage on the PDA and discovers that Phillips recorded himself running through the woods from Redfang. As Ian watches, Phillips drops the PDA and is hauled away by Redfang. Ian searches for Phillips and hears Redfang. When he panics, he almost stumbles into a bear trap. Cal finds him, and tells Ian to stop following him. When Ian refuses, Cal attacks him. They fall down a slope and land next to a gate leading to an underground tunnel. They work together and get the heavy gate open.
Fenton brings the injured CJ to the infirmary to get her fly bite looked at now that it’s swelling. He insists on finishing the assignment, and tells her that he can read her just like she can read others. Fenton assures her that her friends care for her, and that she cares for them.
Ian and Cal enter the tunnel and Ian figures out that Cal has been looking for it the entire time they were in the woods. Cal believes that it’s a Gnome bunker but the legendary Redfang lives there. He plans to become a legend himself by escaping Tower Prep. When Ian suggests they work together, Cal figures that he’s suggesting that CJ is part of his team. He doesn’t believe it because he figures that CJ would have told him. As they go, Ian unravels the vest to leave a trail of string so they can find their way back.
Once they’ve been treated, Suki and CJ go to the observatory. Suki examines the specimens they collected and realizes that they come from different parts of the world, and there’s no one place where they’re all found.
As they explore, Cal compliments Ian for once about using the string, but Ian accuses Cal of thinking only of himself. Cal explains that he was a star athlete and everything came easy to him. When he was brought to Tower Prep against his will, he took out his frustrations by joining the Buffer team. Something behind them breaks the string, and the two students hear Redfang growling in the distance. Gnomes approach Ian and Cal… and keep on running, scared of Redfang, who is pursuing them. The two students flee to a chamber, but the Gnomes find them. They attack Ian and ignore Cal, until he tells them to let Ian alone. Cal and the Gnomes leave, while Redfang enters the chamber and approaches Ian.
Gabe tries to leave the infirmary but Jenny persuades him to stay and keep the pressure off his foot until morning. She mildly flirts with him and convinces him to stay, at least for the moment. However, he soon gets impatient and leaves.
Ian wakes up outside next to the gate. He tries to go back after Cal but the gate is too heavy to move b himself. He tunes in the translator and hears Cal, who is with the Gnomes. Cal hopes that Ian is listening, and tells him that he came to the tunnels so he could join the Gnomes. He asks Ian to keep an eye on CJ, and then the Gnomes place one of their helmet on him.
Gabe and Ian get to the observatory and tell Suki and CJ what happened. Ian explains that Redfang knocked him out and then took him out of the tunnel to protect him from the Gnomes. He admits that he doesn’t know why Ian rescued him, and then tells CJ about Cal.
Emily goes to the infirmary to see Gabe, but discovers that he’s gone. Ray and Fenton arrive to talk to their field trip partners, with Ray bearing flowers for Suki. Emily shows them the map and they wonder what Ian and the others are up to.
Some time later, Ian is telling the students of Tower Prep a new late-night horror story: of how Cal was turned into a Gnome and lurks in the woods with Redfang, eager to attack any student that tries to escape.
In the caves, “Redfang” removes his hood, revealing that he’s Phillips. He tells other students who have taken refuge in the tunnels that it’s too late for Cal, and their best weapon against the Gnomes is to maintain the legend of Redfang.