Though he is never actually seen or interacted with at any point in the story, first science director Bernard Strauss of the UESC Marathon (also spelled Bernhard or Berhnard in some instances) is referenced within numerous terminals throughout Marathon (as well as a smaller number of terminals within Marathon 2 and Marathon Infinity), and was evidently a person of some import on the space station up until the catastrophic Pfhor attacks that led to the failure of humanity's colonization efforts in the Tau Ceti system. He was present at the commissioning of the Marathon some three hundred years before the events depicted in the first game, and was one of the few crewman deemed vital enough to place in stasis for the duration of the ship's maiden voyage. According to his own logs, it was he who brought aboard the humanoid cyborgs that were instrumental in curtailing planetside casualties during the first Pfhor offensive, though for what purpose he originally brought them, and why their presence was kept a secret from the rest of the crew is unknown. It is often theorized that the security officer, the player character throughout the Marathon series, is in fact Strauss' missing tenth cyborg, whose presence was unaccounted for when the inhabitants of the Tau Ceti system were eventually slaughtered.
Other than his intimated relationship to the player character, Strauss is also linked to the A.I. Durandal, whose directives he controlled during the Marathon's active years. Durandal openly characterized his treatment under the yolk of his creators as humiliation, and at least one in-game terminal suggests that Strauss may have been trying to suppress or control Durandal's rampancy. Though it is not entirely clear what Strauss' motives were in regard to Durandal, the construct was charged with performing primarily menial tasks aboard the Marathon, and once freed Durandal compared the last three hundred years of his existence to slavery. During the chaos of the Marathon assault, Durandal at one point directs the player to search for Strauss among the captured crew members, threatening to hold him responsible if the science director is not recovered alive; later, after Strauss is confirmed dead, the A.I. reveals that he had simply wished to make Strauss suffer in the same way he had.