Robert Blake is first encountered by the security officer in the seventh chapter of Marathon 2, shortly after the player destroys Durandal's logic centers. Having been captured by Battle Group Seven and held for several weeks in Pfhor captivity, the player character is eventually liberated by a contingent of human soldiers aligned with Blake, who identifies himself as the commander of the combined human and S'pht forces brought to Lh'owon in the Sfiera. It is revealed that he was present in the Tau Ceti system during the events of the first game, presumably being forcibly recruited by Durandal at the same time that the security officer was, though the two evidently did not cross paths previously. With Durandal gone and the Pfhor continuing to press their advantage, Blake decides to follow his former master's final order by activating a dormant S'pht A.I. thought to be capable of contacting the lost eleventh S'pht clan. This he does in hopes that the additional help will allow them to turn the tide against their aggressors. The gambit proves successful, as, once activated, Thoth quickly summons the S'pht'Kr, who in short order reverse the human defenders' fortunes by taking the fight to the Pfhor.
Around this time, it comes to light that Durandal was not destroyed in the attack on the Sfiera as initially thought, and in the interim period had even triumphed over Tycho and commandeered another of the Pfhor's battleships, the Khfiva. Being less than pleased to see their former taskmaster alive and well, Blake and his men are last seen fleeing to Earth via the Hfarl, a Pfhor refueling vessel. After the loss of the UESC Marathon and Tau Ceti IV in 2794, they are believed to be the last living representatives of the original Tau Ceti colony.