The movie opens with a video explaining the Duke of Edinburgh Award, which is a challenge designed for young people to connect with nature, work together as a team, and gain personal growth through outdoor experiences in the scenic Scottish Highlands. The story follows a substitute teacher, <a href="/actor/jonathan-aris">Mr. Carlyle</a>, who takes three troublemaking boys—<a href="/actor/lewis-gribben">Duncan McDonald</a>, <a href="/actor/riam-gordon">Dean Gibson</a>, and <a href="/actor/viraj-juneja">William DeBeauvoir (DJ Beatroot)</a>—along with a well-behaved student, <a href="/actor/samuel-bottomley">Ian Harris</a>. These boys are in trouble for setting a bathroom on fire, and Carlyle hopes the outdoor challenge will teach them discipline and teamwork. Ian, however, seems genuinely interested in earning the award for the right reasons, unlike the others who are more interested in mischief and rebellion.
As their adventure begins, Carlyle leaves them to find their way to the campsite using a map, while he drives ahead in the minibus. Not far into the trek, the group notices a suspicious figure seemingly stalking them. During their hike, DJ, who is more concerned with his appearance, resists getting into muddy boots, and in a disturbing discovery, the boys find a severed foot buried in the ground. The story takes a darker turn when Dean pulls out some hash that he got from his cousin. Things escalate quickly when he lights it, creating a large spark that causes a flashback to a makeshift joint he rolled using part of the map, leading to a chain of chaotic events. Dean then attempts to record an impromptu rap video, adding a comedic touch amidst the tension.
The group encounters a farmer, played by <a href="/actor/james-cosmo">James Cosmo</a>, riding his tractor through the fields. The boys ask him for directions to the campsite, and after helping them, DJ leaves his stickers and a mix CD on the farmer’s tractor, showing his playful, rebellious nature. Their journey is interrupted by a figure dressed like the Duke of Edinburgh, played by <a href="/actor/eddie-izzard">Eddie Izzard</a>. The boys ask the Duke, but he unexpectedly fires his rifle, forcing them to run and devise a plan to escape. Dean tries to create a bomb using a gas lighter and matches, inspired by a terrorist handbook he downloaded, which fails to ignite. Duncan then comes up with the idea to use DJ’s music CD, hash, and a makeshift wick to ignite the lighter, successfully setting the Duke’s leg on fire and forcing him to retreat.
Meanwhile, back at the police station, <a href="/actor/kate-dickie">Sergeant Morag</a> informs <a href="/actor/kevin-guthrie">PC Hamish</a> that she suspects Duncan might be a terrorist based on surveillance footage, mistakenly thinking his name is Doonkhan Mak Doonahld. Her goal is to solve a seemingly minor bread theft, but she believes her case might save their station from closure. They investigate the area, finding the supposed “bomb” and residual hash on surveillance footage, though PC Hamish inadvertently eats rabbit feces, adding comic relief.
The boys reach the campsite again, where they find Mr. Carlyle with a burn on his leg. Suspicion grows that he could be the Duke in disguise, prompting them to act. Duncan sneaks into the minibus and runs Carlyle over, causing panic. They decide to stage the incident as a suicide by letting the vehicle roll off a hill, ensuring it crashes into the woods below. As they contemplate their next move, they are surprised by the Duke’s wife, <a href="/actor/georgie-glen">Duchess</a>, and the Duke himself. Realizing Mr. Carlyle isn’t their killer, the boys make a swift escape. During the chase, Ian falls into a ditch, but DJ and Dean help cover him with dirt and sticks to hide him from the Duke and Duchess. Night falls, and conflict intensifies within the group as DJ and Dean argue about their plans, with Dean criticizing DJ for trying to imitate a gangster background that he doesn’t truly come from.
Later, DJ finds himself in a barn full of farmers, who recognize his music and enthusiastically accept his mix CD. The farmers also give him rabbit feces infused with powerful magic mushrooms, which leads him to have a wild, inventive rap session. At the same time, Ian is rescued by the Duke and Duchess, and Duncan and Dean hurry to help, reuniting the group. DJ’s new psychedelic experiences allow him to see things differently, and his encounters with the farmers provide moments of levity.
As dawn arrives, the boys tend to Ian’s wound and reflect on their experiences, with Ian expressing feelings of being ignored and labeled a loser. Duncan reassures him that they’re all outsiders, linked by their shared sense of being considered failures. Meanwhile, Morag and Hamish return to the station, where the <a href="/actor/alice-lowe">Superintendent</a> criticizes their obsession with the terrorist threat, emphasizing that bread theft is a more pressing issue for the community.
Determined to confront the Duke and Duchess once and for all, the boys pursue them with the help of the rabbit feces, turning it into a tool for their plan. They army themselves and chase the villains through their hideout, which leads them dangerously close to a cliff. The antagonists mock the boys, blaming all the world's problems on the younger generation, but Dean counters that the adults are to blame because they left the world in a terrible state. Just as the villains prepare to execute the boys, the minibus finally rolls off the cliff and crashes onto the hunters below, crushing them all—an unexpected yet fitting climax. The boys then find Mr. Carlyle injured but alive, and, in a desperate act, revive him using magically potent powder and a sharp fork. Carlyle, upset and battered, lashes out at them but is silenced when Morag and Hamish arrive, still pursuing the villains. They discover the stolen bread in the back of the minibus, exposing Carlyle’s secret and saving the boys from further trouble.
In the end, the boys are regarded as heroes for their daring deeds. They prepare to head home, giving a group of girls their weapons and instructions to signal for help if needed. As they part ways, they notice one last observer—a hunter watching them from a distance—hinting that their adventure might not be over yet.
