Vriess was an engineer aboard the smuggling ship the Betty. Vriess and the crew of the Betty were responsible for delivering several kidnapped civilians to United Systems Military scientists aboard the USM Auriga, and he subsequently became involved in the Xenomorph outbreak and infestation aboard the ship. Vriess was paralyzed from the waist down, requiring a wheelchair for mobility. Despite this handicap, he was one of four survivors of the Auriga incident, along with Ripley 8, Johner and the Auton Annalee Call.