Born in Hollabrunn, Lower Austria, Dr. Eva Engelsen is part of the behind-the-scenes staff at Mojave Fields AFB, CA -where S.O.F. 303 is based. As the base's Chief Medical Officer, she is responsible for the overall health of the operators as well as all other employees and is also often called upon to advise on aspects of the 303's missions that pertain to her expertise.

As well as being a physician, Eva is also qualified as a psychiatrist and a surgeon; meaning she is well-equipped to meet any physical or mental health needs her patients may have. She also has a law degree. She joined the CIA on the recommendation of her father; a former operations officer of the Agency stationed in Vienna, after having moved to the US with him and her mother. She lives in the Bay Area with her wife, with whom she is happily married.