Carissa is pretty sure this guy isn't lying but if he is she is going to show him a lot of Fireballs. She can only cast one per day but presumably someone will courteously leave him chained to something for as many days as it takes.
"What do we believe about what happened. That someone caused Pilar to be with us and our departure not to be the secret it was intended to be. That Nidal detected you leaving the Forbiddance and attacked. That - despite knowing where you were - they went through the villa and killed most of its defenders. That they Fireballed your room - how many rooms are similarly destroyed -"
"I haven't done a full inventory but an explosion took out half the west wing, that's how they entered, and the banquet hall and the four rooms adjacent to it are burned as thoroughly."