McGonagall advises Harry to be cautious

Harry delivers Umbridge's disciplinary note to Professor McGonagall, who questions him about the truth of his actions. After confirming that Harry indeed challenged Umbridge in class, McGonagall warns him to be careful, explaining that misbehavior in Umbridge's class could have serious consequences. She advises Harry to tread cautiously around Umbridge, as she is reporting directly to the Ministry of Magic.