The Athame was the source of Nemfection in Winter, the attack was to free the Nemfected Lea. Did she think Nameless or Laplander were potential vectors from Lea? Maeve was the last known Nemfected member of Winter, or that they may me used by Maeve? She had Recap spying on Maeve before her infection.
There is definitely something more going on. Nameless is clearly bound by Winter Law OR is content to give that impression for the moment. Does she think him a sleeper for someone else? The Circle perhaps? Do we have a new candidate for Cowl? Or is he a separate member.
Cowl knew Bob contained the Word of Kemmler, Nameless worked with Kemmler rather than as an Heir so would have known about Bob, and Nameless has a honking great Bear Spirit Skull in his office. Was Justin working for Nameless? As a lawyer he could have made Harry legally disappear with Justin, he could have bound Justin like he did Laplander, or used Laplander to do this for him when Kemmler was finally apprehended. Justin now bound takes Bob and waits for the next Starborn to appear. This may make the Elaine is Kumori theory much stronger. As a Demi -god, Nameless is much stronger than a wizard but still weaker than Mab. That fits Cowl. The Word would fix this, powering up Nameless to full godhood and capable of overpowering Mab breaking the link to Winter perhaps? That the Future Winter Knight prevents this is very apt. It parallels Butters own future Knighthood in the same book, whic was deliberately commented upon in Skin Game. Sacrificing the Erl King a Vassal of Mab in the power up and the rest of the Wild Hunt weakens Mab.
This is why the Circle and Outsiders are working together, they both want Mab weakened.
My favourite candidate for Cowl is now Nameless. I need to re-read the Nameless/Harry interactions.