My thinking is that it was before, Grave Peril while she was held captive by Bianca. Then like a encysted parasite or an anthrax spore,it slept in her brain, first metagating her mental health symptoms that were attributed to controlled feeding by Thomas. Nothing was noticed because it as so gradual, until it was in the perfect position to not only undermine the White Court, but the whole of the Accords.
We might find out eventually, but it seems like an odd choice to me. Justine was a young girl dating the outcast son of the White Court King. Lord Raith was clearly willing to use Outsiders, as he trained Madge to summon Behind. I don't see the value in infecting Justine at that time.
As the book said, her getting infected when Justine got close to the leader of the White Court makes more sense to me.
And some people just unscrew the box and replace the hard drive.
That analogy would have to go with... Amanda Beckitt.
In keeping with the computer analogy, Starborn would be a combination of fire wall+antivirus then?
... This actually makes me think of Nemesis as something like the agents from the matrix, it can jump in and out of any hardware connected to it's primary system... Or would that be more like agent smith, who over writes the program already there with its own?
Beside would be a lot like Agent Smith, but I doubt Beside is as powerful as Smith. Maybe Smith from the first movie, where he's limited to one host. The mass host thing just seems wrong to me.
But yeah, a Starborn has built in protection against the Outsiders, which would be like having protection from his ports being manipulated. His ability to control them or have power over them, which I think was mentioned by Lash, would be that his outbound ports are open to send power at them, and likewise they can't close their own inbound ports against him.
This makes sense to me and clarifies some things. The last one though leans towards your second observation - since HWWBs has had an active role in the background for much longer. So it being locked up in Lea was more like Mab didn't want her second infected and was 'burning' the infection out. And HWWBs didn't like being quarantined (as you say), but slipped out and got Maeve.
Yeah, I think Mab would have preferred Beside be trapped, but not in Lea. She's too important.
It does make me wonder if Mab's threat to get vengeance on everyone involved would include Harry, if his attack on the Winter Spring played a role in Beside escaping and infecting Maeve.