Marathon 2 takes place seventeen years after the events of the first game. Durandal, one of the three AIs from the colony ship UESC Marathon, sends the player and an army of ex-colonists to search the ruins of Lh'owon, the S'pht home-world. He does not mention what exactly he is looking for, although he does let slip that the Pfhor are planning to attack Earth and that being on Lh'owon may stall their advance.