At the end of the Forerunner-Flood war, Mendicant Bias attacked the Lesser Ark in an attempt to prevent the firing of the Halo Array, correct? Or perhaps he simply thought of it as the last Forerunner holdout... In any case, my question is this: If Mendicant knew about the Halos, why did he not attack a specific Installation, rather than the heavily protected Ark? If he disabled one Halo, 1/7 of the galaxy would be unaffected by the Halo effect if the array was activated, thus allowing Flood in that section to survive. Edit: Or were the Halos put in place via portal as the attack was happening? That would make more sense...