Seattle’s morning traffic was usually a deadlock, but it broke as the Ghost flew north on Interstate 405. And there were no black Cadillacs following me. I settled into the soft leather seat for an all-time favorite drive: Seattle to Spokane.
Interstate 90 cut across Washington State in nearly a straight line. The highway’s most obvious thrill was its mountain pass, where the Cascade Range gathered sheered blue-granite peaks that stabbed the sky like battle swords. Running north to south, the mountain range separated the west’s evergreen forests and the east’s desert plains. Most drivers considered it an anticlimax when the road dropped out of the mountains to the eastern flatlands. The mountains moved to the rearview mirror and the road leveled onto a basalt platform so bare and abandoned that it looked lunar. At that point, travelers cranked up the radio.
But as a geologist, I leaned forward. This deceptively bland desert was a battleground in the great war that still rages today. This particular skirmish began in the late 1920s, when an idiosyncratic geologist named J. Harlan Bretz walked across eastern Washington. Bretz wanted to document the area’s mineralogy and topography because the land looked unlike anything else in the United States. Though it looked flat, Bretz discovered the dense basalt actually rolled gently toward the west. He also found deep canyons that appeared suddenly, with plumb-straight sides and level bottoms. Like bathtubs hundreds of feet deep. Bretz named the area “the great scablands” and called the sudden depressions “coulees.” But most puzzling was the loose soil gathered in the middle of the coulee floors. The rocks didn’t match the surrounding geology, not for hundreds of miles.
There’s a pervasive theory in geology called uniformitarianism. It’s a long word for a basic idea: the landscapes seen today were formed by continuous forces exerted over millions of years. Geologists claimed that eastern Washington’s flatlands were the result of slow and steady erosion over eons of time. But Bretz, who had a PhD in geology, claimed the evidence said otherwise. This strange geology, he wrote, could only result from massive flooding. In fact, one flood.
“A flood of biblical proportions,” Bretz wrote.
Maybe it was the word biblical, but the science journals started banning Bretz’s academic papers. His peers mocked him in print. Vilified his geology. Conspired to discredit every bit of his geology. For the next thirty years “Bretz’s flood” was treated like amateur science.
Yet Bretz never wavered.
The Great Depression came. World War II began. And ended. The 1950s ushered in unprecedented prosperity, along with developments in science and methods of documentation, such as aerial photography. The pictures of eastern Washington taken from airplanes showed solid rock that rolled, undulating like beach sand when a wave suddenly pulled from shore, rippling the surface. Geologists took soil samples inside the coulees and discovered the minerals came from western Montana, hundreds of miles away. To figure out how it got there, engineers devised computer models based on the facts.
And the facts showed anything but uniformitarianism.
Scientists concluded the following: During the last Ice Age, a glacier suddenly melted. The ice cap was so large it smothered most of Montana. Miles and miles of frozen water. And it melted in less than twenty-four hours. A sudden ocean, the water swept toward the west, crashing through present-day Idaho and scouring miles of eastern Washington. The hydraulic force was so powerful it stripped away every bit of vegetation, then began cutting through solid rock like a buzz saw, slicing through hundreds of feet of volcanic basalt. On the water’s surface, boulders bigger than houses bobbed and tumbled, washing all the way to present-day Portland, which would have been submerged under as much as four hundred feet of fresh water.
Not millions of years. Not even years.
The flood happened in one day. Perhaps even hours.
At age ninety-six, J. Harlan Bretz shuffled into Washington, DC, to receive geology’s highest honor, the Penrose Medal. Bretz’s “flood of biblical proportions” was now scientific fact, geologically proven.
And I couldn’t help giving thanks for Bretz every time I saw eastern Washington’s otherworldly topography. A scientist who thought for himself. A geologist who knew that some of Earth’s best puzzles surpassed human comprehension. I was still feeling buoyed by the man’s bravery as the Ghost floated past Eastern Washington University. On the edge of campus, I parked beside a small State Patrol building and carried my muddy purse inside. Washington had two crime labs—the one in Seattle that I visited last night, and this outpost beside Idaho’s rugged border that specialized in rural crimes. Poaching, mining intrigues, wildlife. And this lab was led by a forensic geologist named Peter Rosser.
He was talking on the phone when I walked into the lab. His clothing seemed coated with a fine layer of dust. The Western shirt with pearl snap buttons, the jeans and snakeskin boots, all of it looked like his investigations were settling on him in sedimentary layers. But as I waited for him to finish the conversation, I felt a familiar itch. I knew how to run every test for this clay, but I couldn’t risk doing them. Not unless I wanted the evidence tossed out of court later because the same agent who collected the evidence also did the forensics. Conflict of interest. And Rossser had skills that rivaled geologists in the FBI’s lab.
“Yes, indeedy,” he said into the phone while gesturing to me. He was opening and closing his big paw of a hand, like a kid greedy for a present. “I’m gonna ride to the edge of town.”
I took the mud ball from my Coach bag and dropped it into his palm.
“Tumbleweeds?” He peeled away the glove’s deflated fingers. “I’m mighty partial to tumbleweeds. Means fewer people.”
He pinched off a piece of clay and put it in his mouth.
“Psst,” I whispered, “that stuff might be poisonous.”
He ran his tongue along his lip, making sure he didn’t leave any clay on his mouth, then finished up the phone call.
He hung up and turned to me. “That’s some mighty fine clay.”
He meant grain size. Fine covered grains measuring about .002 millimeters. Mighty was Rosser’s Western vernacular.
“And possibly deadly,” I said.
“I can taste kaolinite.” He smacked his lips. “Least I won’t get the runs.”
An aluminum silicate mineral, kaolinite was used in everything from kitty litter to clay pigeons. It was also the definitive ingredient in the antidiarrheal medicine Kaopectate.
Rosser, still smacking his lips, gathered some chain-of-command forms and began filling in the blanks—what arrived, with whom, when.
“What d’you need from this, Raleigh?”
“Basic mineralogy first. Particularly anything that poses a health threat. Then provenance.”
Provenance was location, the geological location of a specific mineral. Geology had some distinct advantages among the forensic sciences. The biggest might be that while most investigators were searching for the needle in the haystack, geology could actually shrink the haystack. Provenance was particularly helpful when a soil was highly unusual. It worked like a fingerprint, distinct and telling.
“Hate to say this,” Rosser drawled, “but you caught me at a bad time.”
He pointed his pen at the lab’s outer wall. Stacks of cardboard boxes rose to the ceiling, their brown sides marked with terms such as Igneous, Felsic, and Foliated metamorphics.
“I’m getting outta Dodge,” he said.
“Pardon?”
“Ridin’ into the sunset. Pointed at the prairie.”
“You and Dale Evans?”
He grinned. “It’s the lucky cowboy who gets a gal like Dale. But I’m ridin’ solo. Opening my own lab.”
“How come?”
“How come?” He scratched the pen into his black hair, pretending to look baffled. “Those Feds make you drink a lot of Kool-Aid?”
“I’m just wondering. What’s the advantage?”
“Raleigh, if I gotta explain that to you, then I’m wasting breath.” He carried the clay across the room to a stainless steel counter, placing the lump on a glass cutting board. “But you ever figure out why I’m doing this, gimme a holler. I need another forensic geologist.”
He sliced the clay with a sterile scalpel. Each section was about one-sixteenth of an inch wide. He placed them in separate Petri dishes set under a heat lamp but dropped another slice into a glass beaker. Adding ten ounces of distilled water, he capped the container and shook it—hard—then placed it on the counter. The water was brackish, the grains so fine they could remain suspended for days.
“You know the source of this stuff?” he asked.
“Yes.” We both knew I could only divulge so much for legal reasons, and to avoid swaying his investigation. “The clay’s not being used for manufacturing purposes. And it’s probably dug up by hand, perhaps with a shovel.”
“Exposed at the surface?”
“I don’t know.”
Rosser pinched what clay remained on the glass cutting board. Once again, he put it in his mouth. “It’s the consistency of toothpaste.”
“Only it’s not toothpaste. And it might be poisonous.”
As he worked the soil around in his mouth, his eyes were focused on a middle distance between us. I could see light in his dark eyes and thought of what Newton once said, how his scientific work made him feel like a boy standing on the seashore, staring out at the undiscovered truth. “The great ocean,” Newton called it.
Under the heat lamp, the dried clay had turned a pearly white color. Rosser dusted the grains on a glass slide and placed them under the stereoscope. A simple device, almost elementary, the stereoscope had two magnifying lenses that worked separately to give a three-dimensional view of the specimen.
“No maggots.” Rosser stared into the lenses. “Don’t see any excrement either.”
“You didn’t want to check that before eating it?”
“That’s no fun.” He looked up from the lenses. “But then, you probably forgot how to have fun. Working for the government does that to a person.”
He coated another glass slide with petroleum jelly and sprinkled more dried clay over the surface. That slide went under the polarizing light microscope. PLMs were used to find subatomic structures. Beams of white light struck the magnified grains at precise angles, and the refractions revealed a mineral’s “invisible” architecture. When I taught elementary geology—otherwise known as Rocks for Jocks—during my senior year at Mount Holyoke College, I used to explain the PLM to students who hated science by having them read their textbooks through a clear calcite crystal. With a cubic atomic structure—shaped like a sugar cube—calcite produced a double refraction of white light, which showed up as doubled letters on the page. Once a geologist had a mineral’s atomic structure, he was that much closer to pinpointing its identity.
“I thought you rode back to Virginny.” Rosser gazed through the PLM’s lens, turning the knob that adjusted the optical axis. “Couldn’t stay away from Seattle, huh?”
“Something like that.”
During my disciplinary transfer last year—banished to the Northwest by my boss in Richmond—Rosser had run some soil exams for my missing person case. Not only did he nail the mineralogy, but he got provenance down to a pinpoint. It was quite a feat: Washington State had almost forty-three million acres.
He looked up from the scope. “Seattle grows on people. Always check for moss behind your ears.”
I smiled.
He went back to the lens. “Still like working for the FBI?”
“It’s okay.”
“Mmm.”
He looked up again, but I had already turned away, staring at the computer monitor attached to the PLM. It showed the same view as the microscope, where the grains, magnified by hundreds, appeared as random objects tumbling across a clear floor made luminous from the petroleum jelly. I saw linear pieces, oblongs, which looked to me like random bits of hay. Maybe hair from the horses. But some cubic shapes were pronounced. Their sharp edges glowed in a way that reminded me of Richmond’s streetlights on summer evenings, when humidity produced auras around the lamps.
“Haloes,” I said.
“You got it. First guess?”
“Zircons.”
“What I was thinking too.”
I leaned into the monitor, trying to get a closer look. I’d seen zircon with haloes, but nothing as powerful as this. The crystals beamed like flashlights, and I knew only one source could produce that much energy.
I said, “Those are radiation haloes.”
But Rosser had already picked up a dry slice of clay, toting it across the lab, ducking his head under the ropes that hung from the exposed steel I-beams. Nooses and slipknots, forensic samples of restraint and torture and death. I followed him to the Scanning Electron Microscope. It was shaped like a large metal box and produced a near-constant din of squeaks and whirs, like a clock about to break a cog. Rosser tapped a carbon plug into the dried clay and slid it into the SEM’s side opening.
“See if we get a direct hit,” he said.
A metal filament inside the SEM produced electrons, similar to what happens in a lightbulb. But the SEM had magnets that focused the electrons into a single beam. When aimed directly at an object, the beam could draw an object’s shape and structure, down to the finest details. SEMs were essential to crash evidence forensics, detecting structural flaws that may have existed before impact—weaknesses in airplane wings, faulty headlights. It was used on excavated pieces of the Titanic and revealed how the cold water caused the ship’s hull to become brittle and more vulnerable to impact with ice. Although it worked best on cleaned samples, I didn’t have time to wait for the grains to settle from the brackish water. Rosser, sensing my urgency, hadn’t even asked if I wanted to wait.
“Thanks,” I said.
He nodded and clicked the mouse that switched the monitor from a 3-D display of shapes to bar graphs. We knew these minerals were cubic; we needed to know what they were, exactly. Several “unknowns” were already appearing on the screen. Hay, I figured. Dust, barn particles. But kaolinite appeared. Then zircons, identified as zirconium by the SEM.
“I’m two for two,” Rosser said.
“Quit gloating.”
“There’s your radiation.” Rosser pointed at the screen. Thorium and uranium were the next minerals identified.
I glanced back at the beaker on the counter. A thin dark line of sediment was beginning to form across the glass bottom. Heavy metals dropping out first. Thorium, uranium. While I waited for the SEM, Rosser walked back across the lab. Turning left at the ropes, he opened the bottom drawer of a file cabinet and removed several boxes that were wrapped in a lead apron.
“Washington’s got a passel of radioactive deposits.” He carried the metal containers to the stainless counter. “I keep samples for comparison purposes.”
“Wrapped in lead blankets.”
“I look stupid to you?” he asked.
“You ate that clay.”
As if to say touché, the SEM pinged. The scan was complete and the bar graph looked like a rigid rainbow, each color representing another element. The “unknowns” were there, but with high levels of aluminum and silica. The kaolinite, I decided, the aluminum silicate minerals. I read down the rest of the list.
“Selenium,” I called out to Rosser. “In high concentrations, right behind aluminum and silica.”
“Check the periodic table.”
“Come on, just tell me.”
“I’ll give you a hint. Arsenic’s neighbor.”
Arsenic was number 33 on the periodic table. “Thirty-two or thirty-four?”
“Four,” he called out. “And sometimes as poisonous as its neighbor.”
“Good thing you ate two servings.” I walked over to a bookcase across from the SEM and used both hands to pull out the monstrous Kerr’s Optical Mineralogy. The definitive source, Kerr’s described more than five hundred different minerals. The tome was my personal manual when I worked in the FBI’s mineralogy lab, and the pages of clear photographs felt as familiar as a family album.
Selenium’s periodic table symbol was Se, and Kerr’s described it as a grayish-purple semimetal. Selenium often formed poorly shaped crystals but sometimes appeared as tiny acicular—hair-like—structures. The mineral was used in glassmaking, paint pigments, and photovoltaics. When I suddenly heard a series of distinctive rolling clicks, I looked up from the book.
Rosser was waving the small instrument over the clay. The closer it came to the soil, the louder and quicker the clicks. Click-click-clickclickclickclick. Radiation detector.
I said, “The clay is used for therapeutic purposes.”
“Where—death row?”
I went back to Kerr’s. The notes mentioned selenium’s toxicity but without much detail. I walked over to another computer, set aside from the exam equipment. Rosser told me the lab’s security code and I logged onto the Internet. After several Google queries, I had some basic information. Selenium was necessary for good health, but in high concentrations the mineral was toxic. In humans, symptoms of selenium poisoning included weak and/or rapid pulse, labored breathing, bloating, abdominal pain, and dilated pupils. In animals, the symptoms were about the same, and included a stiff gait. North and South Dakota had soils that carried naturally heavy concentrations of selenium, and in that area pastured animals were known to accidentally poison themselves by eating too many field-grown grains. However, it was difficult for farmers to catch the toxicity early because symptoms were vague—stomach problems, difficulty breathing, disorientation . . . symptoms that sounded eerily similar to “Emerald Fever.”
I turned to Rosser. He was placing the radioactive materials back inside the metal boxes, covering them with the lead apron.
“Any chance you get provenance,” I said, “before you ride off into the sunset?”
“It’s that serious?”
I stared at the screen. Most people recovered from selenium poisoning, the article said. There was an antidote, which was easy to administer.
But animals were another matter. Particularly horses. There was no antidote. Every incident of selenium poisoning was fatal.
“Yes,” I said. “It’s that serious.”