As a spacecraft hovers away from a planet, a humanoid alien consumes a dark, bubbling liquid, which ultimately leads to his disintegration and the cascading of his remains into a waterfall. This event sets off a bio-genetic reaction with far-reaching consequences. Fast forward to 2089, archaeologists Elizabeth Shaw and Charlie Holloway make a groundbreaking discovery in Scotland—a star map linking various ancient civilizations. They interpret this as a call to action from the "Engineers," an advanced race considered to be humanity's forerunners.
Backed by the elderly CEO of Weyland Corporation, Peter Weyland (played by Guy Pearce), a scientific vessel named Prometheus is built to journey to the distant moon LV-223. As the crew travels in stasis, the android David operates the ship, ensuring everything runs smoothly. Upon arrival in 2093, the crew is briefed by Meredith Vickers, the mission director, to avoid any contact with the Engineers without her explicit permission. Before their departure, they receive a haunting message from Weyland, who has passed away during the voyage.
Upon landing near a massive artificial structure, the crew begins their exploration, uncovering stone cylinders, a monolithic humanoid statue, and an Engineer’s corpse, leading them to believe the species may be extinct. Secretively, David takes one of the cylinders back onboard while the others leak a dark liquid, which makes contact with some worm-like organisms on the ground. As a storm approaches, the crew hurries back to Prometheus, inadvertently leaving team members Millburn and Fifield trapped inside the structure. David manages to communicate with an unseen being within a stasis pod, receiving the ominous instruction to "try harder."
In the ship's lab, the revelation that the Engineer’s DNA closely matches humans sends shockwaves through the crew. David, in a risky move, taints Holloway’s drink with the dark liquid. Shortly after, Holloway and Shaw consummate their relationship. Meanwhile, chaos ensues inside the structure as a snake-like creature attacks Millburn, and corrosive fluid from it incapacitating Fifield. When the crew returns, they find Millburn's lifeless body. David pursues his own investigations, leading him to a control room containing a living Engineer in stasis along with a star map that highlights Earth.
Holloway's fate becomes dire after consuming the dark liquid, leading to a swift and grisly infection. He is brought back to Prometheus but is met with resistance from Vickers, who ultimately has to incinerate him to prevent the spread of the infection. Surprisingly, a medical scan unveils that Shaw, despite being sterile, is pregnant with an alien life form. In a desperate bid for survival, Shaw uses Vickers' automated surgical equipment to remove and subdue the squid-like being inside her.
At this stage, it is revealed that Weyland has been in stasis onboard Prometheus, aiming to confront the Engineers in hopes of eradicating his own aging. He calls Vickers "Father" as he prepares to venture out to the structure. In a tragic turn, Fifield, now mutated by the dark liquid, launches a catastrophic attack within the hangar before being slain. Captain Janek speculates that the mysterious structure belonged to the Engineers and acted as a platform for a bioweapon gone rogue. He also deduces that it is essentially a hidden spacecraft.
When Weyland and his team awaken the Engineer, things take a grisly turn as the alien decapitates David and eliminates Weyland along with his crew. Shaw manages to escape just as the Engineer activates its vessel intending to unleash the dark liquid on Earth. Janek, recognizing the imminent danger, launches a lifeboat and collides the Prometheus into the Engineer's ship, while Vickers finds refuge in an escape pod.
The disabled spacecraft crashes, crushing Vickers beneath its wreckage. Still, Shaw survives and discovers her alien offspring alive, now in a considerably larger form. David’s severed head warns her via intercom that the Engineer has indeed survived the collision. The Engineer breaches the lifeboat's airlock and launches an aggressive assault on Shaw. In an unexpected maneuver, Shaw unleashes her alien offspring, which subdues the Engineer by forcing a tentacle into its throat.
By recovering David's remains and utilizing his knowledge, Shaw initiates another escape attempt using an Engineer spacecraft. Her goal? To journey to the Engineers’ home world and uncover the terrifying truth behind their intentions to annihilate humanity. As she takes flight, a chilling revelation occurs—an alien creature erupts from the chest of the Engineer, hinting at the horrors that await.
