First thing, right off the bat, the secret agent observed the message on her office door. Couldn’t miss it, like Poe’s “Purloined Letter,” hidden in plain sight.

On a square piece of cardboard, cut from a cardboard box, and taped to the door with gray Duct tape, in playful Magic Marker reds and yellows surrounded by sprinkled glittery starries was the message: “THOUGHTS HAVE MASS.”

He’d been briefed. They’d told him she said things like that. Evasive. So he knew he’d found the right place.

Rebecca had never before been visited by a secret agent, but she wasn’t nervous. She’d jumped fences before. There’d been consequences, but never before had it come to this.

As usual, the door to her office was left slightly ajar for students. The agent didn’t bother knocking and closed the door tight behind him.

As soon as he entered her world, Rebecca stiffened.

It was perfectly obvious to her what he thought of himself, or the image he was trying to project… power… authority… tinted glasses… narrow tie… a little too thin for his tall, solid, skeletal infrastructure… too much coffee… irregular sleep. Directed.

Even before initial pleasantries, he seated himself and then unlocked and began shuffling through papers in his leather brief case like she didn’t exist or mean as much as he did.

Then he looked up: “Dr. Mendelssohn, I’m pleased to meet you. I notice that you spell your last name with two esses.”

“It’s the way it was spelled, originally, in the old country. For personal reasons, many of my family’s immigrants to America dropped the second ess when they got here to distance themselves from a past they wanted to forget. I was born with only one ess, but legally added the second ess after I learned more about my past. The name’s actually Mendelssohn-Heikkinen. I’m married.”

“Of course. And your husband is a professor here, too, I believe?”

“Professor of Modern American Literature, but I’m sure you already know that. Am I being charged with something? And what agency did you say you were with?”

He didn’t answer her questions directly, like inferring that he’d be the one doing the asking. He said: “A technical paper you recently submitted for publication in an international peer-reviewed journal has caught the attention of some important people.”

Rebecca remained silent, then said, “… and?”

“I’m just here to learn what I can,” he said.

“About me or the paper? Have you even read my paper?”

“I’ve seen it.”

“Can I assume that you have no idea what it’s about; that you don’t even know what language it’s written in?”

The agent leaned back in his chair and took a moment to calculate the best way to answer her, or if he should. She was smart, all right. She understood home field advantage, keeping the ball in her own court. If he didn’t know what she was talking about then she could say just about anything she wanted to say and get away with it. Without a warrant, he couldn’t make her speak in the vernacular. She would have to trust him. Confide in him. At training school in a class about interviewing techniques he learned that sometimes the best way to get a subject to confide was to first confide something about yourself without giving the store away.

He removed his glasses. His eyes met hers.

“Defense intelligence,” he said. “And, no, you’re not being charged with anything and, yes, you can assume that your paper was pure Greek to me… equations with hieroglyphic notations about a German mathematician who died before our Civil War…”

“His name was Riemann, Bernard Riemann,” Rebecca interjected. “He said that thoughts have mass.”

The agent leaned back in his chair. He forced a stony grin.

“I noticed that on your office door. Sounds like secret code.”

“It’s mathematics… advanced.”

He fumbled for his next thought… “Not my thing… I’m not a mathematician. I grew up in Indiana… Gary, a steel town back then. Got my first security clearance in Vietnam. This is my first assignment with the agency. All I know is that somebody told my boss at the Detroit office to get one of his agents up here to find out about a certain professor of mathematics at a small university way up north in the Upper Peninsula. I’ve been driving all night. I’m not here to discuss the technicalities of your paper. We’d just like to know a little more about you, that’s all… your habits, where you grew up, acquaintances…”

“… like what I eat for breakfast?”

“… yes, things like that,” he said with a forced smile.

“Apparently somebody higher up thinks you’re an interesting person with interesting ideas… maybe they’re looking for background before offering you a big position. I don’t know. I’m just doing my job.”

“And you think you can do that without a common language?”

“I’ll do my best,” he said, putting his darkened glasses back on, straightening his tie and then, reaching into his briefcase, he pulled out a 9X12” glossy black-and-white photograph, which he slid across Rebecca’s cluttered desktop for her to inspect.

Anybody who didn’t know what they were looking at would have thought they were looking at an aerial photo of a desolate, empty, barren, high desert landscape; deep canyons; dry creek beds; rocky cliffs crumbling into sand… corroding volcanic peaks, shades of metallic gray and shadows, but, oddly, scattered about the landscape, like specks of lint on a black tuxedo, you could just make out, if you looked closely enough, tiny little white spheres, slightly luminescent -- delicate spheres, clinging to the sides of granite cliffs or wedged into and peering out of a crack of rock.

Holding it at arm’s length examining the photograph with a Mona Lisa smile, Rebecca said: “Funny how deceiving appearances can be.”

“So, you’re familiar with the photograph? I first saw it just yesterday. My immediate superior handed it to me as I was going out the door and told me to make sure you saw it. It looks like a moonscape to me. Maybe a NASA photo of an asteroid. He said you’d understand. Do you?”

“Of course! I love this photo! I was at the KMS Fusion lab in Ann Arbor the day the photo was taken. I was part of a team of academics invited there to tour their facility. The company was started in the 1960s by University of Michigan physicists who were interested in pursuing inertial confinement fusion…”

She paused to observe his reaction. There was none.

“They’re doing cutting edge work there,” she went on, “but I assume you’re familiar with most of that…”

His face remained blanketed.

“… or maybe not. They manufacture microscopic-sized glass spheres, fill them with a common isotope of hydrogen and ship them off to Lawrence Livermore National Laboratory where, one by one, they become targets for the most powerful laser in the world – Shiva – two-stories tall, the length of a football field, capable of producing nanosecond bursts of energy greater than all the energy being consumed along the entire West Coast at that moment…”

Rebecca took a deep, cleansing breath… she loved telling this story…

“… Shiva the laser has many arms,” she went on like she would do in front of her advanced mathematics classes and was why her classes were so popular. “Like the mythical Hindu goddess, Shiva directs its energy through dozens of energy guns all aimed at one of those microscopic glass spheres. Like an attacking army, the physical positioning of the energy guns encircling the target is critical, probably the most critical thing. It determines the mathematical angles at which each burst converges on the spherical target and how they interact, creating interacting shock waves interacting in an out, moving at the speed of light towards a non-Euclidean point where -- if the math is right -- a living thermonuclear star is born, giving off more light and energy than all the energy it took to create it.”

Handing the photograph back to the agent, Rebecca said,

“I’ll bet you don’t know what this is a picture of. ”He took the photo from her, looked at it and shrugged. “My superior just told me to make sure you saw it, and to make a note of your reaction, not what it was.”

“It’s a picture of the head of a pin, magnified thousands of times by an electron microscope.”

“A pin? It looks like the surface of an asteroid.”

Rebecca told him to notice the little white things scattered about, maybe a dozen of them. “Those are the glass spheres I was telling you about.”

“On the head of a pin?” he repeated, looking at the photograph, rubbing his clean-shaven chin, which smelled like Aqua Velva. “That’s incredible! A pin… and those tiny glass things…”

Then, like catching himself in the middle of a fall, the agent remembered what he was there for -- raw intelligence, “product” for the higher ups to piece together. Like in Nam, counting bodies. “Just find out what you can,” his superior had told him; that, and to make sure she saw the photograph… nothing more.

He looked around the room, fishing for clues… family pictures, diplomas, books, scattered papers. He decided to chance a technical question, realizing he’d be stepping onto her court.

“What does your paper about a nineteenth century German mathematician have to do with microscopic glass spheres on the head of a pin? Just curious.”

Rebecca settled back into her chair and tried to look calm. But she felt suddenly tense. Maybe he was just playing dumb. She was sure he had to be aware of the Defense Department’s institutional predisposition to classify new discoveries to keep them out of the hands of our enemies, created, imagined or real. Maybe he knew about the department’s keen interest in the cutting edge field of inertial confinement fusion. It could be a better way to build a bigger bomb. But her paper was about an 18^th century German mathematician. Only at higher levels where the language was understood could the connection be known. The young agent, who’d spent his graduate school years in Vietnam, surely lacked the advanced training in the language of mathematics to see the connection, himself.

That’s when it hit her! The real reason for this little visit. Even he didn’t know the real reason. Maybe his immediate supervisor didn’t know the real reason, either. But somebody who knew the language knew, and now Rebecca knew and a coldness went through her. He was being used to deliver a message and he didn’t even know it. It was the preferred way of sending code. Unlike the U.S. mail and Bell telephone systems, it left no trace unless the messenger was alive to talk. The message was a warning. Be careful. We’re aware of you. Work with us or you’ll be sorry.

She would have to reply.

She got up out of her chair, crossed her arms and walked around the room. She stopped to look at various posters she had hung up here and there like the one on her front door… messages in Magic Marker. “THERE’S NO SUCH THING AS EMPTY SPACE,” said one. “WHATEVER IS POSSIBLE, DEMANDS TO EXIST,” said another.

She turned to face the agent, looked him squarely in the eye and said, “No.”

The agent looked puzzled. “No, what?”

“No, I will not remain silent. No, I will not allow myself to be confined within your fence around the Torah.”

“What are you talking about? What fence? What Torah?”

Rebecca was in no mood to answer questions, but to make demands. ”You can tell your immediate supervisor that I said the people need to know what’s possible; that the photograph says everything I want to say, angels dancing on the head of a pin and that I, for one, a simple Jewish girl who grew up in a strictly Orthodox family in Queens, but years ago jumped the fence around the Torah – that I, I!, can prove we can turn those tiny glass spheres into stars with all the energy of the universe at our fingertips. The mathematics tells me so. I know what’s possible. And the people need to know… that we’re not running out. And you want to keep it a secret? No!”

The room fell wordless.

“I don’t mean you, personally,” Rebecca said “At this point you don’t know what’s going on, but what will you do when you do? I do and I say ‘no.’”

Through her closed office door they could hear the muffled steps and chatter of students in the hall.

“You’re right,” the agent said in a tight voice. “Maybe I really don’t know what’s going on here. But you can be sure that I’ll deliver your message. I don’t know what the reaction will be.”

When it was time for the agent to get up and leave, Rebecca asked him if she could keep the copy of the photograph. “I want to mail it to an old friend of mine who might be interested in this sort of thing.”

The agent had to think quick. The photograph was not classified – not yet, at least. It would be a way for him to show trust. He was sure there would be follow-up visits. “Sure,” he said. “Who’s your friend?”

“A former student,” she said.

She didn’t tell him that her former student was now an investigative reporter at a major Detroit newspaper.