Author's Note: Keeping to the elemental character of these stories, I can't always promise to be in chronological order, so sometimes I will go back a bit in time. This is one of those occasions. Just think of it as a flashback...

Carbon

C 6 12.017

Non-metallic and tetravalent, meaning there are four electrons able to bond. Carbon is one of the few elements known since antiquity; its name is derived from the Latin carbo meaning coal. The fourth most abundant element in the universe by mass, it is present in all known life forms and in the human body the second most abundant element (about 18.5%) after oxygen. It is known to form almost ten million different compounds, the largest of any element, and is the basis of organic chemistry.

Part One - Carbon's First Allotrope Graphite (and Graphene)

Graphite, from the Greek "to write", is the soft allotrope of carbon. Pencils contain graphite mixed with clay to make it harder; pencil marks are bits of graphite that break off and adhere to the paper when pressed.

Doctor Molhotra's examination of Sherlock was methodical and quick, but he wasn't getting much co-operation. Still, it was better than it used to be, when the ten year old would panic at the sight of him, and he needed the help of two male nurses to restrain him while the examination took place. Now the boy just sat there in his hospital bed with a sullen look on his face. The doctor had some sympathy; he must have known by now that the examination was always done just before an ECT session. Before using the stethoscope on the child's thin chest, the Asian doctor put down his pad and pencil on the bed. He would transfer the statistics to the chart kept at the nurses' station later: pulse, respiration, blood pressure. He'd also draw a blood sample, to make sure that the current lithium blood serum level was right. It was proving hard to get the dose right, not only because the patient was a child, but also because his weight kept fluctuating. They'd had lots of problems over the months with that- sometimes he would eat, and then stop, requiring a gastric tube. Getting the exact dosage right in such circumstances was always tricky, especially now that they were trying to wean him off of it.

Just as he jotted down the latest pulse reading, his pager went off. A quick glance down at the device and he dropped the pad and bolted from the room- a code up on the next floor, one of the teenage patients.

Impassive, Sherlock watched the doctor leave the ward. As soon as the door clicked shut, he picked up the pad and the pencil. He left the top sheet as it was, but pulled a dozen perforated pages out from the back of the pad. If he was lucky, it would be ages before they were missed. Folding them in half, he tucked all but one of the sheets into his book. Left with one clean sheet, he began to draw a grid, seven boxes down and eighteen across. He used the edge of his book to be sure that the lines of his grid were straight. Sherlock looked at the page that the doctor had completed and saw the date, then transferred that date to his sheet and began to fill in the boxes of the grid with the letters he could remember: H, He, Li, Be, B, C, N, O, F, and so on. There were a few gaps, but he reached number 56, and then drew a line from it to a space below his grid, then another table, this time with only two rows and fourteen columns. The second row of this table he linked back to AC, number 89 Actinium.

Sherlock had trouble keeping track of the days, because they all seemed to be so similar here. Now that he had a pencil, he could keep a calendar in his book, so he wrote the date on the blank page at the back. Reading the book last night, he'd memorised the 103 elements*, and he was determined to keep track of what he was forgetting each time they took him away for treatment. The periodic table would be his test.

When Molhotra returned over an hour later, Sherlock heard his footsteps coming down the hall. After all these months, he knew the difference between his stride and that of a nurse. In a flash, he hid the pencil beneath the hospital bed mattress, and slipped the graph in the back of the book, which he shoved back on the bedside cabinet.

When the doctor entered, Sherlock was still sitting there, looking as if he had not moved at all in the interval. Still, it's better than when he was first here; then he was virtually catatonic. The doctor took the blood sample, and then picked up the pad. Now where had his pencil gone? Had he taken it with him? He sighed- probably left it up in the coded patient's room.

oOo

The consulting detective was pacing, his hands were steepled beneath his chin as if in prayer. The office was a typical academic's room- book-lined, with filing cabinets and a large white board on one wall. The board was covered with a mixture of mathematic equations and chemical notations. John watched as the consulting detective walked back and forth between the white board and the door. Occasionally, his hands would come apart and make odd gestures.

The other occupant of the room looked a little concerned. "Is he alright, Doctor Watson?" The man's Russian accent was still detectable beneath his English.

"Yes, Professor Novoselov. This is how he thinks."

The professor tutted. "Please, you are not a student; call me Kostya."

The doctor smiled to reassure the physicist, who seemed entirely too young to be a Nobel Prize winner. The medal had been awarded two years ago, and was the reason why Sherlock was here. The medal had been stolen, and the Manchester police had no clues at all. The University's own security systems were not particularly brilliant. ("Idiots, John. They seem more concerned about student bicycle theft than they do with the potential for intellectual property crime against one of the finest minds of the twenty first century.")

It took a lot for Sherlock to be impressed by someone, but he was by Sir Konstantin Novoselov, a physicist who started his career in Russia, moved to Holland to do graduate work and then ended up in Manchester, working alongside his fellow Nobel Prize winner, Professor Andre Geim. On the train up from London, John had been an audience of one for a lecture.

"He's a physicist who is also an Honorary Fellow of the Royal Society of Chemists. Absolutely ground breaking stuff, John. Over ninety peer-reviewed research papers on fascinating subjects, like mesoscopic superconductivity. But unlike an ivory tower academic, he's also capable of seeing the applicability of it all. I read his paper on gecko tape and it was just riveting."

"Gecko tape? What's that? It sounds like some...I don't know, something like that Gorilla Glue you used to fix the shower head at Baker Street."

Sherlock looked down his nose at John. "Really, John, I know medicine is an applied science, but you really did specialise too early. Gecko tape is synthetic setae, a dry adhesive that first used polyimide fibers stuck to scotch tape. It mimics the unique process that allows a gecko to climb a wall, only it's much, much better at it. It was discovered by Novoselov in 2000; now they've moved on to use carbon nanotubes. It has applications in everything from nanotechnology to joint replacements."

"Is that what he got the Nobel prize for?"

"Oh, no. That was for something really exciting- his work on graphene."

John's face must have betrayed his confusion.

Sherlock rolled his eyes. "Really, John, when you were in Afghanistan did you just put your brain into cold storage? It's just the most important scientific discovery of the century."

John sighed. That's me relegated to the back of the classroom. "Before starting on another long lecture, Sherlock, please remember we have only ten minutes before arriving at Manchester Piccadilly station."

The brunet narrowed his eyes. "Alright then, one crash course. Graphene is an isolated single isolated atomic plane of graphite. Think of a sheet composed of carbon that is only one atom thick; it's so thin that it is effectively two dimensional. Its hexagonal crystalline structures make it look like chicken-wire under an electron microscope. It's a superconductor of electricity, and it's the strongest material ever known. It will be the basis of almost all integrated circuits of the future. It can be used in everything from desalination plants to solar cells."

John looked a little sceptical. "That sounds...like a little too good to be true?"

Sherlock shook his head. "Let's just bring it closer to your comfort zone, doctor." He didn't disguise his sarcasm. "Graphene has a molecularly gatable structure, which makes it perfect for microbial detection and diagnosis, so even in general medicine there will be huge benefits. They are already talking about using it to serve as an artificial retina; just think, John, of the consequences for all those blind people out there in the world."

While John was trying to wrap his head around that idea, Sherlock continued. "For me, personally, the great advantage is that it will speed up and reduce the cost of electronic DNA sequencing- the backbone of modern forensics- oh, and that's also likely to help medical professionals beat diseases that have baffled your lot for centuries."

John decided that he was impressed. And looking now at the 38 year old professor who was watching Sherlock pace, the doctor decided that it now mattered more to him that the medal should be recovered.

To buy more time for Sherlock to consult his mind palace, John decided to ask the Professor about the medal. "What is the actual medal like?"

Kostya shrugged. "A lot less exciting than what it means, if you think about it. What a lot of people don't realise is that two medals are given- one that's solid gold, which the Prize Committee assume you will put in a vault somewhere -and I did do by the way- and then another one that's bronze, which is for public display or actually wearing, if one goes to that sort of event, which I don't." He looked down with a grin at his tee shirt, jeans and trainers.

"In both cases, the medals are only 66 millimeters in diameter- so a bit over two and half inches for you Brits- I know that you don't think in millimeters. Not very thick- each year varies in width depending on the value of gold at the time it is struck. Since 2008, the gold medals are no longer 24 carat gold- it's 18 carat on the inside, just plated with 24 carat. Maybe the thief thought the medal in the cabinet was gold? But if so, it's weird. I mean both my bronze version and the one for Andre Geim were displayed side by side in the cabinet in the faculty senior common room, but they only took mine."

Sherlock stopped in mid-stride and turned to the professor. "You said you think a sheet of your work might have been stolen on the same night. Can you tell me more? What was on it? What did it look like? Can I see it?"

Here the Russian looked embarrassed. "Well, I am not sure that it was stolen. It disappeared that night, but it could have been…misplaced. I'm a little chaotic when I am working on things in draft." He gestured to the wall. "The university installed this smartboard for me, but I really prefer to use paper and pencil. So, the day after the medal was stolen, I realised the last sheet of my current project was gone."

He gave a little laugh. "It's not even very exciting stuff- certainly not worth stealing; it's just an elaboration of something that is already out there in the public domain, so…on second thought, I don't think anyone would actually steal it."

He unlocked his desk drawer and pulled a file out, opened it and handed over some sheets of white foolscap pad pages, with very faint pencil scribbles. Sherlock took the last sheet and laid it on the desk, and then got his pocket magnifier out. He bent over the desk, looked at the writing it for a few seconds and then stood up straight again with a puzzled look on his face.

"Professor, why do you make your own pencils?"

Kastya grinned. "How do you know that? No one has ever realised that before."

"Graphite in pencils is mixed with clay. The carbon composition allows transfer; the clay makes it harder, so it will hold a point. This writing has been done with a pencil that is harder than a 10H, which is the hardest availble. Is it…what I think it is?"

"You're right. I use a graphene residue, rather than just plain graphite. There is just enough graphene in the graphite mix to give it the hardness needed to be used as pencil lead, so I don't mix it with clay. Call it a conceit of mine."

"OH!" This was whispered. Sherlock's hands were brought together under his chin as if in prayer. Then decisively, the detective began to explain. "Stealing the medal is a decoy, professor; someone is after your residue. It's not about what you wrote; it's about what you wrote it with- your special pencil! And the thief hoped that in the furore over the theft of the medal you wouldn't notice that the sheet was missing. Presumably, your graphene is leftover from your manufacturing process?"

"Yes, but it's not difficult to manufacture graphene anymore, there are dozens of companies that do it commercially now."

"But not the way you did it."

"Well, I suppose not. I use the residue from my very first experiments in my pencils and that was secret. Does that matter?"

"Oh, yes, indeed; it matters a great deal."

Now Sherlock started pacing again. "Just three months ago, the EU awarded Professor Jari Kinaret from Sweden's Chalmers University a grant worth €1 billion, am I right?"

"Yes, of course. We're one of the universities involved in the consortium winning the FET funding. There are over 126 projects involved."

"Did you get what you wanted?"

Kostya looked a little sheepish. "Actually, we got more. We were awarded €54 million. It was a bit awkward really as both Andre and I are on the Strategic Advisory Council advising the management team about the fifteen work packages involved."

Sherlock's smile was beginning to blossom. "And who was left out of that research funding?"

The professor tilted his head curiously. "Why does that matter?"

"Oh, it provides motive."

The professor gave it some thought. "Actually, it's the Koreans who were the biggest 'losers' if you put it that way. I mean, it's EU money, so the awarding team tended to have a European bias. The decision was made to exclude companies and organisations that are involved in graphene screen production. I mean, it's pretty much the basic start of manufacturing; the harder research work needed now is in applications. The Koreans are the leading manufacturers, Samsung in particular."

Sherlock's smile was now broad. "I don't suppose you have any graduate students from Korea here, do you?"

"Um, as a matter of fact, we do- Joon Park and Pak Soon, both brilliant graduates of Sungkyunkwan University and involved in our work here."

"Then I suggest that the Manchester Police and your University Security arrest the pair and search their premises very carefully. If we've managed to catch them before they could send the sheet of your notes back home, then your secrets will be preserved. No doubt, somewhere in their safe keeping will also be found the medal."

Three hours later, Sherlock smiled again when their train pulled into Euston Station. He showed John the text he'd just received.

6.12pm You were right! Medal and work recovered. One of my *pencils* is on its way to you in thanks. Kostya

Author's Note: * In 1989, which is when Sherlock was in the clinic, there were only 103 elements discovered. Since then another 20 have been added to the Periodic Table. Graphene is real, as are Professors Novoselov and Geim, both 2010 Nobel Prize winners. The €1 billion funding is real, too; the European Commission committed to support major scientific initiatives on Graphene over a period of 10 years- under the Future and Emerging Technologies (FET) Flagship Projects. If you think silicon stimulated the growth of computing and mobile telephony, wait until you see what graphene is going to do!