The story begins with a group of Marines, led by Sarge, being sent to investigate a distress signal sent from a research facility on Mars called the Olduvai Research Station. The facility, run by the Union Aerospace Corporation (UAC), has been conducting genetic experiments on humans and opening portals to another dimension known as “The Ark.”
As the Marines explore the facility, they encounter gruesome scenes of carnage and chaos, with scientists and security personnel transformed into aggressive mutants after being exposed to a mysterious genetic virus. It’s revealed that the virus was created by Dr. Samantha Grimm (played by Rosamund Pike), John Grimm’s sister, during genetic experiments gone wrong.
As the Marines battle their way through waves of mutants, they uncover the true nature of the research being conducted at the facility and the horrifying consequences of tampering with genetic engineering and interdimensional portals.
In the climax of the film, John Grimm confronts his sister, Dr. Grimm, who has become infected with the virus and mutated into a powerful monster. With the help of his fellow Marines, John ultimately defeats his sister and destroys the portal to The Ark, preventing the spread of the virus to Earth.
In the end, Sarge, having become corrupted by the power of The Ark, attempts to kill John and his remaining teammates. John manages to defeat Sarge in a brutal showdown, and the surviving Marines escape from the facility before it is destroyed.
Overall, “Doom” is a fast-paced and action-packed adaptation of the video game franchise, featuring intense combat sequences, gruesome horror elements, and a storyline centered around the dangers of scientific experimentation and the consequences of playing god with genetics.