In the harsh terrain of Ghazni Province, Afghanistan, a highly skilled U.S. Army Special Forces unit led by the experienced Chief Warrant Officer Wally Hamer, alongside Master-Sergeant Kenny Tanner and a capable trio of non-commissioned officers including Sergeants Vince Degetau, Joe Trinoski, Tim Cole, and Pete Sadler, joins forces with CIA operative Benjamin Keynes. Their mission is crucial: to locate the elusive Afghan cleric, Mohammed Aban, whose influence is shrouded in mystery. Hamer carefully briefs his team, emphasizing the seriousness of their task as they prepare for the challenging terrain and potential dangers that await them.
Upon their arrival in the region, the Special Forces members team up with Abdul, a local guide well-versed in navigating the rugged landscape. Together, they embark on a perilous expedition into the mountains, where Aban's legendary ability to conceal himself has made his existence almost mythical. As they traverse the unforgiving terrain, teamwork, mutual trust, and adaptability become vital in overcoming the numerous obstacles that arise.
As the team delves deeper into the dangerous mountain landscape, they are unexpectedly ambushed by violent assailants, leading to the heartbreaking loss of Trinoski. Although they respond with force and take down several attackers, a chilling mystery unfolds when the bodies inexplicably disappear, leaving a cloak of unease in their wake. That night, a strange glow captures their attention, transforming into two inexplicable lights that launch into the sky and vanish.
In the midst of grappling with this eerie occurrence, they attempt to call for a resupply helicopter, only to find their communication equipment malfunctioning. The hardships mount as their already battered truck struggles to navigate the harsh terrain. As night descends, they hear distant helicopter noises, yet their own communication remains dead silent. In a desperate attempt to signal for help, they attempt to send a distress flare but are met only with silence.
Frustration simmers among the team as they choose to cache Trinoski’s body and seek refuge in a safer location. However, morning brings a new horror: the gruesome remnants of Trinoski’s violent end lay scattered across the rocky outcroppings. As they progress, they discover unsettling triangular markers crafted from sticks, hinting at supernatural forces at work.
Through mounting physical and mental fatigue, they stumble upon a cave, providing temporary shelter and a chance to regain their strength. Inside, they encounter an enigmatic old man who offers them food and drink. Notably, Sergeant Sadler observes something curious beneath the old man's garments – a piece of a British army uniform from the 19th century.
Sadler recounts the tale of a British regiment that vanished in the Afghan mountains, sparking further intrigue among his comrades. The following morning, Sergeant Cole witnesses the old man seemingly conversing with himself. Peering through his night vision goggles, he is startled by the sight of robed figures carrying swords.
In a moment of panic, Cole opens fire, inadvertently hitting the old man. Amidst the chaos, Abdul urges the team to bury their unfortunate host, while Keynes asserts the need to move forward, concerned that they may attract unwanted attention. As they push onward, Degetau begins to experience intense stomach pains.
Attempting to alleviate his thirst, he finds his canteen inexplicably filled with sand, a grim reflection of their dire situation. The group's fear escalates as they stumble upon an uncanny valley that appears to have materialized out of thin air. Tensions heighten when they are confronted by a blinding light during the night.
As Tanner and Cole investigate the source, they are instantly vaporized into oblivion. The next morning, Abdul warns Keynes that they have inadvertently ventured into something incomprehensible. The medic’s despair culminates in a tragic act as he steps off a ledge, overwhelmed by the weight of their grim reality.
As the soldiers' anxieties reach a boiling point, they confront Keynes for answers. In a moment of eerie calmness, Keynes reveals a thermal imaging recording showcasing the shocking truth: a triangular entity hovering just beyond their sight, with several figures, including Mohammed Aban, converging upon it and disappearing from existence. This revelation—linked to the CIA's ongoing study of these phenomena since the 1980s—shakes the team to their core as they realize their expedition has been covertly monitored, adding a layer of conspiracy to their harrowing journey.
Keynes theorizes that this otherworldly force ties back to ancient Indian mythology involving 'Vimanas', suggesting that the eerie lights and apparitions are manifestations of an age-old power. Distressingly, Keynes coldly suggests they are expendable, fostering distrust among the ranks. This tension reaches a critical point when the team leader mysteriously disappears at dawn, casting a shadow of dread over the remaining soldiers.
As their supply dwindles dangerously low, they delve even further into the merciless desert landscape, driven by an insatiable curiosity. There, they encounter the mythical vimanas at the site of the British regiment's tragic fate. Overcome with panic, Sadler opens fire into the unseen vessels, only to be swiftly incinerated. Abandoning their comrade, Keynes and Degetau flee, haunted by the gut-wrenching screams echoing through the desert night.
On the verge of collapse, Keynes discovers an oasis, its cool waters a brief sanctuary amid the aridity. His relief, however, is shattered by the chilling sight of Hamer’s lifeless body nearby. Overwhelmed, he succumbs to unconsciousness. Upon awakening, the distant sound of a helicopter draws him into action as he fires a flare gun in sheer desperation. In a simultaneous display, flares erupt from the valley below, illuminating the landscape in blinding light. As the mysterious phenomenon reappears, two ethereal beings emerge from its radiant center, propelling Keynes into a trance that replays his past encounters.
In this altered state, he finds himself suspended above a hospital bed, clutching the talisman he had obtained from Aban’s dwelling. Observing from a sterile room, medical professionals and a military officer express a mix of fascination and apprehension. While in this trance, Keynes utters the chilling words: > "It will save us all..." The film concludes by pulling back to reveal Keynes' wife, who is left in a state of suspense, oblivious to the dreadful fate that awaits him, her words underscoring the profound uncertainty surrounding his fate.
