Frederick Watson Collopy, director of the New York Museum of Natural History, felt a prickling of irritation on the back of his neck as he exited the elevator into the museum’s basement. It had been months since he’d been down in these subterranean depths, and he wondered why the devil Wilfred Sherman, chairman of the Mineralogy Department, was so insistent on his coming to the mineralogy lab instead of Sherman’s coming to Collopy’s office on the fifth floor.

He turned a corner at a brisk walk, his shoes scraping the gritty floor, and came to the mineralogy lab door-which was shut. He tried the handle-locked-and in a fresh surge of irritation knocked sharply.

The door was opened almost immediately by Sherman, who just as quickly closed and locked it behind them. The curator looked disheveled, sweaty-not to put too fine a term on it, a wreck. As well he should, thought Collopy. His eye swept the lab and quickly fixed on the offending package itself, soiled and wrinkled, sitting in a double-ziplocked bag on a specimen table next to a stereozoom microscope. Beside it lay a half-dozen white envelopes.

“Dr. Sherman,” he intoned, “the careless way this material was delivered to the museum has caused us major embarrassment. This is nothing short of outrageous. I want the name of the supplier, I want to know why this wasn’t handled through proper procurement channels, and I want to know why such valuable material was handled so carelessly and misdelivered in such a way as to cause a panic. As I understand it, industrial-grade diamond grit costs several thousand dollars a pound.”

Sherman didn’t answer. He just sweated.

“I can just see the headline in tomorrow’s newspaper: Bioterror Scare at the Natural History Museum. I’m not looking forward to reading it. I’ve just gotten a call from some reporter at the Times-Harriman something or other-and I have to call him back in half an hour with an explanation.”

Sherman swallowed, still saying nothing. A drop of sweat trickled down his brow and he quickly wiped it away with a handkerchief.

“Well? Do you have an explanation? And is there a reason why you insisted on my coming to your lab?”

“Yes,” Sherman managed to say. He nodded toward the stereozoom. “I wanted you to take a… take a look.”

Collopy got up, went over to the microscope, removed his glasses, and put his eyes over the oculars. A blurry mess leaped into view. “I can’t see a bloody thing.”

“The focus needs adjustment, there.”

Collopy fumbled with the knob, sweeping the specimen in and out of focus as he tried to find the right spot. Finally, he found himself staring at a breathtakingly beautiful array of thousands of brilliantly colored bits and pieces of crystal, backlit like a stained-glass window.

“What is it?”

“A sample of the grit that came in the package.”

Collopy pulled away. “Well? Did you or someone in your department order it?”

Sherman hesitated. “No, we didn’t.”

“Then tell me, Dr. Sherman, how did thousands of dollars’ worth of diamond grit come to be addressed and delivered to your department?”

“I have an explanation-” Sherman stopped. With a shaking hand, he picked up one of the white envelopes. Collopy waited, but Sherman seemed to have frozen up.

“Dr. Sherman?”

Sherman did not respond. He extracted the handkerchief and dabbed his face a second time.

“Dr. Sherman, are you ill?”

Sherman swallowed. “I don’t know how to tell you this.”

Collopy said briskly, “We have a problem, and I’ve now got”-he checked his watch-“only twenty-five minutes to call this fellow Harriman back. So just go ahead and lay it out for me.”

Sherman nodded dumbly, dabbed yet again at his face. Despite his annoyance, Collopy felt pity for the fellow. In many ways, he was basically a middle-aged kid who never outgrew his rock collection… Suddenly, Collopy realized it wasn’t just sweat the man was wiping away-his eyes were leaking tears.

“It’s not industrial diamond grit,” Sherman said at last.

Collopy frowned. “Excuse me?”

The curator took a deep breath, seemed to brace himself. “Industrial diamond grit is made from black or brown diamonds of no aesthetic value. Under a microscope, it looks like what you’d expect: dark crystalline particles. But when you look at these under the microscope, you see color.” His voice quavered.

“That’s what I saw, yes.”

Sherman nodded. “Tiny fragments and crystals of color, every color in the rainbow. I confirmed that they were indeed diamond, and I asked myself…” His voice faltered.

“Dr. Sherman?”

“I asked myself: how in the world did a sack of diamond grit come to be made up of millions of fragments of fancy color diamonds? Two and a half pounds’ worth.”

The lab fell into a profound silence. Collopy felt himself go cold. “I don’t understand.”

“This is not diamond grit,” said Sherman all in a rush. “This is the museum’s diamond collection.”

“What the devil are you saying?”

“The man who stole our diamonds last month. He must have pulverized them. All of them.” The tears were now flowing freely, but Sherman no longer bothered to wipe them away.

“Pulverized?” Collopy looked around wildly. “How can you pulverize a diamond?”

“With a sledgehammer.”

“But they’re supposed to be the hardest thing in the world.”

“Hard, yes. That doesn’t mean they aren’t brittle.”

“How can you be sure?”

“Many of our diamonds have a unique color. Take the Queen of Narnia, for example. No other diamond has quite that blue color, with hints of violet and green. I was able to identify each tiny fragment. That’s what I’ve been doing-separating them out.”

He took the white envelope in his hand and tipped it out on a sheet of paper lying on the specimen table. A pile of blue grit poured out. He pointed to it.

“The Queen of Narnia.”

He took out another envelope, tipped it over into a purple pile. “The Heart of Eternity.”

One after another he emptied the little envelopes. “The Indigo Ghost. Ultima Thule. The Fourth of July. The Zanzibar Green.”

It was like a steady drumbeat, one pounding blow after another. Collopy stared in horror at the tiny piles of glittering sand.

“This is a sick joke,” he finally said. “Those can’t be the museum’s diamonds.”

“The exact hues of many of these famous diamonds are quantifiable,” Sherman replied. “I have hard data on them. I tested the fragments. They’re diamonds with exactly the right hue. There can be no mistake. There’s nothing else they could be.”

“But surely not all of them,” said Collopy. “He can’t have destroyed them all.”

“That package contained 2.42 pounds of diamond grit. That’s equivalent to about 5,500 carats. Adding in the amount that spilled, the original shipment would have contained roughly 6,000 carats. I added up the carat weights of the diamonds that were stolen…” His voice trailed off.

“Well?” Collopy asked at last, no longer able to contain himself.

“The total weight was 6,042 carats,” Sherman said in a whisper.

A long silence filled the laboratory, the only sound the faint hum of the fluorescent lights. At last Collopy raised his head and looked Sherman in the eye.

“Dr. Sherman,” he began, but his voice cracked and he was forced to start over. “Dr. Sherman. This information must not leave this room.”

Sherman, already pale, went white as a ghost. But after a moment, he nodded silently.