Set: 17 years after the events in Deathly Hallows.
Disclaimer: all these characters belong to JK Rowling, not me.
Minerva McGonagall, Headmistress of Hogwarts, swept along the corridor, her mouth a thin line of displeasure. It was irritatingly typical of Argus Filch that, today of all days, he should insist on taking more than an hour of her time in reviewing and extending the list of items banned at Hogwarts. Most of the objects in question were manufactured and supplied by Weasley's Wizard Wheezes, and at times it had been hard for Minerva to suppress a wry smile as she imagined the pleasure that this knowledge would bring to George Weasley, and would have brought to his brother, Fred. Minerva had no interest in the details and was more than happy to leave the matter up to Filch, knowing as she did that most Hogwarts students were extremely resourceful in obtaining and concealing the banned items whatever he might do. But Filch seemed to take a lascivious pleasure in naming every hated device individually and describing its heinous properties to her. Their discussion had delayed her preparations for the start-of-term feast that evening, and now she was in danger of being late. Reaching the stone gargoyle, she barked the password, the gargoyle sprang aside and she ascended the smoothly revolving staircase up to her study. She strode quickly across the large, circular room that had once been Dumbledore's and into her private living quarters beyond it.
The Headmistress's face softened slightly as she entered the bed-chamber and saw her tartan dress-robes neatly laid out ready for her. Winky the house-elf had anticipated what she would need and got everything ready. Winky had been much happier since she had devoted herself to Professor McGonagall's service, and though she hardly liked to admit it, even to herself, the Headmistress's rather austere life had been made much easier by the many small comforts which the elf provided each day.
Minerva briskly brushed her steel-grey hair and pinned it firmly back into a bun again. She stood as erect as ever and apart from her hair, her appearance gave little other sign of her age. She changed into the dress robes, glanced at herself in the mirror and gave her hat a final tweak. Satisfied, she opened the door and went back into the Head's study.
"You look splendid, Minerva" said the voice of Albus Dumbledore, and she turned to see him surveying her from his portrait, his blue eyes twinkling. "Thank you, Albus" she replied a touch primly. She crossed to her desk and picked up the roll of parchment containing the list of the year's new students. Usually she would read through the list in advance in preparation for calling out the names at the feast, but today Filch's tiresome interruption had left her with no time to do so. She slipped the parchment inside her robes and made for the door.
"Enjoy the feast, won't you? Another year of students to welcome!" called Dumbledore happily, and around the walls, the other headteachers' portraits joined in a chorus of "Yes, yes, enjoy the feast! How lovely to see the new students! Do welcome them from me, won't you?". Phineas Nigellus sniffed and commented "I hope they are up to the standard we would desire". Only the portrait of Severus Snape remained silent. Snape was sitting sideways to her, one elbow resting on his desk, long legs stretched out in front of him, apparently absorbed in a book, and gave no sign of having noticed her at all. Since this was not at all unusual, Minerva did not spare him a thought as she went back downstairs towards the feast.