Dead Space: Downfall

What seemed liked a Unitologists dream in obtaining the Marker, "The creator of all things", became a suicide mission for those aboard the USG Ishimura. As Security Officer Alissa Vincent leads a team of officers to investigate what happened in the freak mining accident below, all around the people on-board slowly become delusional homicidal maniacs. As soon is discovered, alien life has been released at the site of the Marker, and panic ensues, killing everyone in sight. A very insightful prequel as to how it all started...and how it all must end.