Otto Mossberg (firstname.lastname@example.org) writes:
I think Ryan7 was on to something with his theory on how the Covenant found Earth. Remember on the bridge when Cortana says "I'm detecting taps throughout the ship, Sentinels most likely". That last part really seems to say something. I had never given it much thought until I read that theory, but now... It seems to point to someone ELSE being on the ship, not just Spark and company.