Mountaineers Alison, Ed and Rob set out with friends Jenny and Alex for a climbing and hiking expedition in the Scottish Highlands. During a midday break, they stumble upon Anna, a young girl buried alive in a small wilderness chamber who cannot speak any language they understand. Ed guesses she might be Croatian, and the group agrees that she needs to be saved. To reach safety, they decide to cut through toward the nearest village, a choice that requires a dangerous abseil down a sheer cliff called the Devils Drop. The descent turns tragic when Rob’s rope appears to fail, and he plummets to his death. As Alison tumbles to the bottom, debris rain down and she discovers Rob’s rope has, in fact, been cut. A shadowy figure moves away from the cliff top, signaling that the people who already imprisoned Anna are now targeting them.
The rescue attempt spirals into violence. After killing Rob and a failed attempt on Alison, Anna’s captors, Mr. Kidd and Mr. Mcrae, murder two nearby poachers to steal their rifles and open fire as Alison regroups with the others. In the chaos, Jenny is shot and killed, and Anna is nearly swept away by river rapids before Alison manages to pull her to safety. Alex distracts the pursuers by running in the opposite direction, carrying a backpack wrapped in blankets that they mistake for Anna. Thinking there might be money behind the chase, the two men press on, gun down Alex, and force Alison, Anna and Ed to flee deeper into the wilderness toward the town of Annan Mor.
Meanwhile, a Serbian mobster, Darko(/actor/karel-roden), arrives with British mercenaries Andy and Chris. Their goal is to broker a ransom exchange with [Mr. Kidd] and [Mr. Mcrae] on Darko’s behalf, adding an international layer to the already escalating danger. Kidd tries to bluff through the negotiations, recalling a previous kidnapping in Paris tied to a violent past and a family tragedy that still haunts him. Alison, Ed and Anna are intercepted before they can be taken to Inverness by the police, and the pursuit spills into the Beltane festival-lit town.
As the chase continues, Chris fires at Ed, thinking him one of the kidnappers, and is himself shot by [Mr. Mcrae]. Yet Chris manages to warn Darko that Anna is no longer in Kidd and Mcrae’s hands, giving Darko a chance to shift his plan. A brutal confrontation unfolds inside a burning local house where Alison and Mcrae clash. The blaze and violence end with Alison pushing Mr. Mcrae out of a window, saving Anna and narrowly escaping the flames with the help of firefighters. Alison is taken to a hospital, with Anna staying by her side throughout the ordeal.
The aftermath reveals a grim cross-border conspiracy. Kidd nearly escapes with the ransom money, but is captured by Andy using a tracking device and brought before Mr. Rakovic, a Serbian war criminal and Darko’s boss, who is also Anna’s father. RakovicArray has Kidd stripped, tortured, and buried alive in the woods as punishment for the kidnapping. Andy receives the full fee for his services plus the car, and Rakovic notes that he is deeply in debt to him. The tangled web of motives—survival, money, and vengeance—leaves Alison, Anna, and their rescuers to pick up the pieces after a grueling, danger-filled ordeal in the Scottish wilderness.
