While investigating Ilessan Tower, the Vestige will find a note at the end of the dungeon. It mentions the Red Rooks have resources and they are plans for an attack. The Vestige must find a guard to leave this important message to.
Follow the marker to find Patroller Versien and give the note to her. She is surprised to hear the information but is pleased as they now know they can watch out for any reinforcements from the tower under the attack.