There was a minor plot point about the Spirearch suspecting that there was a traitor in his guard - which is why they had to tiptoe around in Habble Landing, or at least as close as Gwen gets to tiptoeing, LOL - but TAW never revealed just who the traitor was. I can't help that it will become a major plot point in future CS novels, Jim just loves to load whole arsenals full of Chekhov's guns, but the sixty-four million dollar question is who? My money is on Reggie Astor - again Jim just loves him some Chekhov's guns, and I get a very Kalarus Brencis Minoris feel off of the sleazy little punk.
Who do you think the traitor might be folks?