Why did Miss Brockway summon Isabel to her office?

Miss Brockway summoned isabel to her office to tell her about the debate they'd been invited to participate in at Zolile High School.

So when Miss Brockway, our principal, called me in and told me that the black school had started a debating society and had invited us over for a debate, I didn’t have any objections. She said it was a chance for a “pioneering intellectual exchange” between the two schools.