Walden cursed herself afterwards, listening to him explore her flat’s little kitchen. Coffee, please—ugh, she blamed the towel round the waist. She should have got rid of him. She didn’t want him there anymore. A one-night stand with an attractive stranger was a reasonable enough response to a normal human urge. A one-night stand with a self-confessed arsehole whom you had to work with—thank God it was Christmas break and she wouldn’t see him for a week or two. She put on her elderly pyjamas and went and got her dressing gown, raggedy white towelling, decidedly unsexy. Then she opened the bedroom curtains and let the winter sunlight in.

She was still trying to think of an opening gambit for that was very nice thank you now please go away when Mark came back in with a mug of coffee—WORLD’S BEST TEACHER—handed it to her, and started putting his trousers on. “I’d better be getting on,” he said. “Mater expects the whole brood to come and kneel before her throne every Christmas. I assume you’re off for the holidays too. See you next term!”

Walden, torn between insulted That’s it?—yes, she’d gone out of her way to signal that the encounter was over, but was he not even going to try?—and enormous relief, said the first thing that came into her head. “I’m going to call it. You do not actually call your mother Mater.”

“I might,” said Mark.

“No.”

“I could.”

“At this point you are approaching self-parody. I don’t believe it. I have known my share of posers,” said Walden, “and I also know that you went to school in the 1990s, not the 1890s. This behaviour, Mark Daubery, is a pose.”

“Posers? Oh, of course. I bet you were an emo,” said Mark.

“Not relevant.”

“Means you were. Point to Daubery.”

“As youth subcultures go, that one was a bit after your time, surely.”

“I always liked younger women.”

“Oh, do sod off,” said Walden, and took a sip of her coffee.

“Sodding off, ma’am,” said Mark. “Sorry! Sodding off, Doctor.” He rescued his nice wool coat from where she’d chucked it onto a chair last night and swung it over his arm. “Have a good Christmas, Sapphire.”

So that was the end of that. Here was Walden, alone in her flat, alone in her empty school, a week before Christmas Day. The coffee was fine. She showered afterwards. Getting dressed proved unexpectedly tricky. She hesitated over her usual skirt and blouse, then over the ancient band T-shirts and the cheap leggings that should have been thrown out years ago, and found herself wondering: Why don’t I have any non-work clothes suitable for a grown-up?