From across the room, Igor anxiously watched. One of the many benefits of being Headmaster of Durmstrang Institute was the accessibility of ordinarily hard-to-get potions, among those being polyjuice. If he wasn't currently transformed into the body of young lady, he would've been nervously twirling his goatee, a compulsive habit he had. Actually, a couple of times his hand went to his chin, forgetting that he was in another body.
As soon as Minerva took her seat and it was decided that she was truly alone, Igor made his move.
Approaching her table, an unfamiliar woman told Minerva, "Room four. He'll be waiting."
The woman walked away, going up the stairs to the rented rooms upon the first floor.
Once inside room four, Igor closed but did not lock the door. He'd timed it just right, so that the hour was up and the polyjuice wore off, transforming him back into his original form. The robes he had worn as a woman was full enough that it still fit him pretty well not that he was a man again.