A way out there possibility: The Praeses have to beat Alice one-on-one and she has to do the same (although the current stalemate suits her fine). Anything else would be a breach of the Rules and there is a far, far bigger player out there who is enforcing them.
I'm thinking something similar to the
Babylon 5 deep back story. The two sides - the low-techs and the high-techs - are still fighting it out as to who has the right prescription for sustainable human happiness. Because letting this happen in an uncontrolled way would just lead to the Great War starting all over again, the power behind the Blink has set aside a tiny patch of the Earth where the two sides can play chess with each other. Going outside that contact area and using extreme methods like orbital bombardment would forfeit the game. Given the power level required to carry out the Blink, the umpires (the AIs, perhaps?) very likely have the capability to inflict catastrophic sanctions on those who break the Rules.
In this game of human destiny, the Town and its surrounding Habitat is the board. Ardent and Gavia are the latest in possibly a long string of pawns sent onto the game board by the Praeses and it is possible that the townsfolk are the pawns of the low-tech side.
Alice is the other side's queen. Like the queen, she is far and away the most powerful piece on their side of the board and, naturally, the Praeses are doing everything to keep her in check and away from other moves that they may or may not be planning.
What does that mean? White queen takes black pawn.
Goodbye Ardent. At least that is probably what Alice is thinking right now.
I wonder if, as in
Babylon 5, the real story will be the pieces deciding that they don't want to play anymore...? Which is, of course, the outcome that the AIs were waiting for all along.
"Who are you? What do you want? Why are you here? Where are you going? Do you have anything worth living for?"
-- Lorien
-- Babylon 5 - The Hour of the Wolf