When Walden turned around with the milk carton in hand, Laura was looking wretched. “I was—that was—terribly unprofessional of me,” she said. “Earlier. I apologise.”

“What?” said Walden again and then while Laura went red remembered all at once: that kiss. “Laura—”

“Look,” said Laura, shoulders squared like she’d spotted another demon to fight, “would you like to get drinks at the Red Lion with me sometime?”

Walden said, “I don’t think that’s a very good idea.”

Laura deflated. “Right. Of course. Sorry.”

“That’s the only pub in the village,” Walden said. “Which means it’s the student pub. So unless you want our first date observed with interest by half of Year Thirteen—plus a couple of Year Tens hiding in the corner and praying we don’t notice them—”

“Oh,” said Laura. She started to smile.

“Counterproposal,” Walden said. “Next time I have a free day—which I’m afraid won’t be till half term, but it’s only a couple of weeks off now—we can catch the train into London and I’ll take you to a little place I know near Camden Town. And then, I don’t know, we can see a film or something. It’s been years since I went on a date but I think I remember the steps.”

“Sounds nice,” said Laura. “I’ll look forward to it.”

“Me too,” Walden said. And with that, exhaustion fell onto her like a weight of stone. She looked at the mug of tea in her hands and could think of nothing worse than trying to stay awake long enough to drink it. “I think I should go to bed,” she said. “Are you sure you’re all right to sit up?”

“Sitting up for an observation is part of my job,” said Laura patiently, “which I am good at. And I was on a night shift, and I’m completely fine. I’ll write my report if you can lend me a laptop or something.”

“Of course.”

“One more thing, though—”

Walden paused.

Laura grinned at her. “I’ve always wanted to know. Did your parents really name you ‘Saffron Walden’? Like the train station?”

Walden, taken completely by surprise, started laughing. “I’ve never been able to decide if that would have been better or worse. No, no. I’m afraid it’s ‘Sapphire.’”

“Oh my God.”

“I know.” It was a beautiful, romantic, totally un-English sort of name. It belonged to someone about as different as could be imagined from the person Dr Walden chose to be. She’d always found it embarrassing.

Laura rallied admirably. “That’s pretty, though,” she said. “Like your—”

She stopped, probably because she’d noticed herself being unforgivably cheesy. Eyes, Walden finished mentally for her, and laughed. “I haven’t heard that one in a while,” she said. “There’s a reason I go by Saffy. I do prefer it.”