Essery worried that perhaps the rumours were true and he did live in his office, but she also didn't find that she minded that much as she got dressed again - it wouldn't do to go up to the Headmaster's office in your pyjamas after all - and grabbed the only bottle of wine she had in her rooms to take with her.
She wasn't sure why, exactly, but at the time she grabbed it it had seemed like the best possible choice. Ice cream was for gossiping with girlfriends. Wine was .... well, for tonight, at least, it was for gossiping unexpectedly with your boss.
Twenty minutes later or so she was on the stairway, rising to his door.