Colony Ship Marathon. Having traveled across the galaxy, it has finally come into orbit around a planet capable of life. But trouble is brewing as the AI's controlling it disappear, break, or go mad. And to top it all off, an Alien invasion.

Can a security officer paired with a unicorn from the future stop the invasion? Especailly when there's a rampant AI in the way?
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Crossover with Marathon. No, Marathon is not Halo.
Rated T for language and future scenes.
Playing the game is not needed to enjoy this story. You will only miss out on some of the inside jokes of the Marathon community.