Fan Casting Marathon

The year is 2494. Humanity is finally making their first steps beyond the Solar System by way of the UESC "Marathon", hollowed out from Deimos, one of the moons of Mars. Three hundred years later, the Marathon reaches Tau Ceti IV and a colony is established. Not long after, a conglomerate of alien slavers and their thralls known as the Pfhor attack the Marathon and the colony with stunning surprise and savagery. A lone security officer, known for being the best marksman and the colony's troubleshooter must stop the alien menace. All the while being torn between the whims of the Marathon's functioning Artificial Intelligences, and discovering his own strange and nefarious origins...