"So you knew." Brightblade's calm statement suggested that she was not at all surprised, even if Arran was still staring at the Matriarch with wide eyes.
"I suspected it for some time," the Matriarch said. "And when he survived that attack, my suspicions were confirmed."
"What gave it away?" Brightblade asked, her expression one of mild curiosity rather than alarm. It seemed she didn't believe the matter a serious problem. Or, if she did, she did an excellent job of hiding it.
"You allowed him to study the Forms," the Matriarch explained. "It's not unusual for young mages to be interested in those, but their teachers generally put a quick stop to that — and rightly so. Yet you allowed him to continue."
The Matriarch cast a short glance at Brightblade, and when no objection came, a pleased smile formed on her lips.