Minerva absorbed this news too, striding over to the girl, Arthur and Glee again. "Yes, in fact do Miss Connors. Quickly." She gestured at her robes. It was odd... surely McGonagall was not a psychic, but put in situation with young students eager to help in situations like this before, it was as if she sensed the natural question on Terry's mind. She would have- and did- ask the same question to a Professor herself. In her case, it was with a Basilisk loose in the castle.
Minerva shivered inwardly at the memory. "I must stress that in Mister Harper's current state, Stupefy may not be the best course. We don't know how much of his mind is his. Best go for something to bind him, if you see him and he's intent on action."