Miss Miller placed her teacup back on its saucer, and settled back into her chair. Her cat, Aubrey, leapt from the floor into her lap, and she stroked him absent-mindedly. “If your office has been broken into, Dean, shouldn’t you be speaking to the police?”

Dean Harper was the professor of zoology at the university, and a long-standing member of the Ornithological Society. He shook his head wearily. “It wasn’t that sort of break-in. They didn’t steal anything tangible.”

“Implying they stole something intangible?”

To her surprise, he nodded. “Indeed. Every year, I prepare an extra credit paper for my top students to take. It’s very hard indeed, and a pass is highly coveted. Only two students have earned distinctions in the past twelve years, and they are both now junior professors. When I discovered the break-in, that was the only thing that had been disturbed.”

“When is the exam taking place?”

“Tomorrow. There’s just not time to write a replacement.”

“So you want to catch the cheat. But surely there must be–”

“Four, Mary. Just four students are good enough to participate, this year.”

“I see,” Miss Miller said. “I have to admit, I’m rather intrigued by the idea of this exam. Let’s see if we can get to the bottom of your mysterious intruder then, shall we? Hopefully it’s one of your candidates, rather than an entrepreneur seeking to make a little money on the side by selling the questions to all of them.”

“Good grief, I never even considered that,” Dean said. “Do you think it’s likely?”

“Honestly, it seems wasteful to try to commodify details of an exam to be sat by just four people, rather than one with a potential purchaser base of a hundred or more.”

“That’s remakably cynical of you, Mary.”

“Thank you, my dear.”

An hour or so later, the pair arrived at the department of biology, where Dean’s office was. It was a long, ornately-designed brickwork building with attractive flowerbeds along its length.

“Which one’s yours?” Miss Miller asked.

Dean pointed out a window, four to the right of the large wooden doors. Like all of the windows on the lower floor, it was tall and quite broad. The bottom two thirds of each window was frosted, to ensure privacy from passers-by. The top third, above head height, was hinged to open inwards, to allow a little air. The window frames were painted in a pleasant arboreal green. Burnt orange azaleas bloomed in the flowedbed directly below the window.

“Very nice,” said Miss Miller. “Shall we go inside?”

Dean led her into the building, past the departmental secretaries, and along to his office. Once he’d unlocked it, she followed him in to find an untidy room crammed with books and papers on every available surface. “You’re going to ask me how I know only the special exam was disturbed, aren’t you?”

“And you’re going to tell me that despite appearances, you know where precisely everything is,” she replied.

“Well, not exactly. But I’d know if it had been substantially rearranged, and I genuine don’t think it would be easy to move many of these heaps without having them go everywhere.”

“Security through fragility?”

Dean laughed. “Something like that. Anyway, the exam is in this draw.” He opened his desk draw, and pulled out a roll of paper. “It’s been unsealed and untied. Nothing else has. Even if the intruder had taken the time to re-tie other papers–and why would they?–they didn’t have access to my seal.” He showed her another roll of papers, this one ornately tied with red ribbon, and closed with a seal of white wax. “So they definitely knew what they were going for.”

“Yes, I see what you mean. Could any of your students have seen you with the exam?”

“Not in any meaningful way. I only ever work on papers when I’m alone. During the hours that I accept student queries, I keep everything I’m working on rolled up on the sideboard.” He indicated a sloppy heap of rolled scrolls of paper to his left. “I’m sure they’ve all been in over the last couple of weeks, while I was working on the exam, but there would have been no way for them to identify it.” He turned, and tapped on the frosted glass of the window. “No peeking over my shoulder, either.”

“So do you have any idea how they might have known what to go for? Do you have an assistant?”

“No assistant, and no idea. I was absolutely the only one who knew precisely which exam was which.”

“How about happenstance? Say my enterprising exam salesman from earlier broke in, got the wrong exam, but didn’t have time to check any others? Your desk draw would probably be a good candidate for a place to look.”

“The break-in happened some time between my departure last night and my arrival this morning. There’s security near the door, and they wander the corridors occasionally, but you’d be safe from observation here, in the office. I find it difficult to imagine someone who went to the trouble to break in would have had just seconds. It takes several minutes at least to copy an exam, and only a few seconds to realize you have the wrong one.”

“Yes, alright, I can see that there would be plenty of time, particularly with an accomplice. So let us assume that your ambitious student either has the larcenous talents to get into your office whilst the guard is on his rounds, or acquires a compatriot to assist. I assume they all live in dorms?”

Dean nodded. “Biology third-years are all in Tatum House.”

“So their alibis are likely to boil down to having been in bed alone.”

“Yes, definitely. Overnight ‘guests’ are grounds for expulsion.”

“Hm. Do you any supicions?”

“No, I’m afraid not. I wouldn’t have thought any of the four would cheat. They’re all quite brilliant, and mostly perfectly pleasant.”

“I suppose we’ll just have to speak to them individually, if possible,” Miss Miller said.

They left the office. Dean locked it behind them. “Got to get a better lock,” he muttered.

“There are always better locks, but there are also always better thieves. A truly determined and resolved criminal can always get to a prize.”

“That’s a disturbing thought. Are you saying I should write my exams in code?”

Miss Miller smiled. “If it makes you feel better. Mainly though, I suggest you change up your security a bit, and just try not to worry about it too much.”

Dean shot her a doubtful look. “You’re rather unsettling today, Mary.”

“I do what I can,” she replied cheerfully.

Tatum House was a bland stone cube towards the edge of the university campus that provided acommodation for a little over one hundred and ten students. Dean Harper consulted a scrap of paper, and led the way to the first student’s room, on the second floor. “Jacob Walters,” he said, when they stopped outside the door. “Very interested in reptiles.” He knocked, loudly.

A few moments, the door flew open to reveal a slim, bespectacled young man of medium height. He was dressed very casually, in a loose shirt and flannel bottoms. He looked at Dean, and his eyes widened. “Professor Harper! I, uh. How can I help? Is everything okay?” He flicked a doubtful look at Miss Miller.

“Good afternoon, Jacob. This is Miss Miller. She’d like to ask you a couple of questions, if she may.”

“Sure.” Jacob now looked utterly baffled.

Miss Miller beamed at him kindly. “Tell me, Mr. Walters, what does your father do?”

“He’s a gold smith,” he said dubiously.

“Excellent. And where would you say the dividing line lay between reptiles and birds?”

“Archaeopteryx of course, but I really…”

Still smiling, she poked her head through the open door, and glanced around the lad’s room, then stepped back. “You have a very untidy room, young man. Thank you for your time.”

“We must be going,” Dean said firmly. “Thank you, Jacob.”

“I…” The young man shook his head ruefully. “Of course. Good afternoon, Professor.” He retreated into his room and closed the door.

Dean gave Miss Miller a very curious look.

“Who’s next?” she asked brightly.

Next, it turned out, was Cameron Honeycutt, a zoological all-rounder and keen member of the track and field team. He had to stoop to exit his room, and was dressed in a sweater and slacks. Positively skinny, he boasted a large, bushy moustache that didn’t quite hide his pronounced overbite, and nibbled his lower lip when Dean introduced Miss Miller.

“How many children did US President John Tyler father?” she asked him crisply.

“Fifteen,” Cameron promptly replied. “Why do you ask?”

“A test of memory,” she replied.

“How did I do?”

“Very impressive. Do you happen to have a spare pencil in there?”

Cameron nodded. He vanished into the room, then reappeared a moment later with a sharply pristine pencil, which he offered to her.

“No, thank you,” she told him. “Good afternoon.”

The next student, Nicholas Nagel, lived on the third floor. “Brilliant, but troubled, and prone to drinking,” was Dean’s evaluation. He knocked sharply on the door.

“Go away,” Nagel immediately shouted.

“Nicholas, this is Professor Harper,” Dean called.

“I don’t care if you’re the Pope himself. Leave me alone.”

“We just wanted–” Dean began.

“GO. AWAY.”

Dean shrugged.

“That’s fine. Who’s last?” asked Miss Miller.

Alexander Cox lived on the top floor. “He’s fascinated by primates,” Dean told Miss Miller. “Particularly monkeys. Seems to think they’re quite a bit brighter than they’ve been letting on.” He knocked on the door.

A few moments later, a dreamy, overweight young man opened the door. “Professor,” he said, without any evident surprise.

“Good afternoon, Alexander. This is Miss Miller. She’d like to ask you a few questions.”

“Of course,” said Alexander.

“Why monkeys, young man?”

“Monkeys don’t pretend,” he said, slowly. “They’re just what they are.”

Miss Miller nodded. “And not apes?”

Alexander shook his head. “No. I don’t like apes.”

“Thank you for your time,” she said.

“Not at all.” Alexander nodded to Dean, and closed the door.

As they made their way back down towards the door of Tatum House, Dean sighed. “Well, that was peculiar. I’m going to get a very odd reputation, and I can’t imagine it helped in the slightest.”

“On the contrary,” Miss Miller said. “I know exactly who your cheat is.”

Who is the cheat?