For the Big Red Button, I see two possibilities:
1) They don't press the button and Alice is annoyed that the villagers have (once again) proven they don't need her.
2) Ardent and Gavia are a distraction sent to get Alice to leave the village, at which point the Prases will attack... and when the button is pressed, Alice will be too far away to help.
3) The entire contents of an ancient library are downloaded via quantum tunnel into the Praeses, immobilizing them. Gavia screams and disappears. (Hey, a red button is a red button)