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"Can-control-" James' voice was punctured with static. "They're-everywhere-"
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He cocked his head as the symbols and numbers scrolled across the NAV console.
The representations of Slipspace vectors and velocity curves twisted across the screen-tantalizingly familiar. He'd seen them somewhere before-but he could not make the connection.
The significance of the above quotes is because of the seeming alliteration to Marathon. The, "he'd seen them somewhere before" quote is something we've seen before 8^) However it wasn't in a dream that Master Chief Petty Officer/Spartan-117/John saw the slipspace (FTL) vectors and velocity curves... he saw them on an ancient relic that he recovered from a mission when he was 14 years old. Anyway, the ancient relic had the exact location of where Halo is located. I'd venture a guess that the Covenant wanted the *probably Jjaro* relic so they could also find Halo (and its' secrets) before the Humans did, but when Reach fell and they saw the PoA flying away, some of the ships followed and got there first. The jump calculations Cortana made weren't entirely random, but did fit in the Cole Protocol. The rest of the crew thinks they're going to the Covenant homeworld, according to the book, when they find Halo. Although it seems like the Captain wanted to see it up close anyway.
Oh yeah, Master Chief might not be the only Spartan left. He brought the clinically dead body of his commrade on board the PoA and froze her, so she might be able to be restored should surgeon work their voodoo magic.