Quicksilver (The Forensic Geology Series, Prequel) Read online

  Shelburne sat on a boulder and folded his arms.

  Walter and I turned to our work. We shed backpacks and took out field kits. Walter claimed the rocky bank and I headed out on the gravel bar to sample the geology mid-river.

  I found a promising spot, a submerged bedrock hump that bridged the water and slowed its flow. A group of boulders gathered, forming deep crevices, a natural hydraulic trap on the river bottom where material coming downstream was likely to get lodged.

  I knelt to sample.

  The water was low. I wondered how much of a rainstorm was needed to saturate the watershed feeding this river. Right now, shafts of late afternoon sunlight glassed the surface. Where clouds shadowed, the river turned inky. A rainbow trout nosed the bottom, the fish multicolored as the gravel. I scanned the riverbed, noting how the rocks and sand acted as riffles, thinking geologically speaking this was an eminently likely site to find grains of gold. Gold is heavy. Water needs a brute-force flow to suspend gold and move it along, and the moment the water slows, the heaviest grains bail out and settle into pockets and crevices. I peered into a large crack. Looking, I abruptly realized, for the telltale metallic flash. I shifted position and did see a flash but it was silver—muscovite mica. Still, my mouth had gone a little dry. I moved on to the next crevice, the next little hollow. The gravel here was mostly buried under silt and sand that had settled out of the river flow. I bent lower and plunged my hands into the water, wetting my sleeves, running my fingers through the sandy bed, unearthing grains of quartz and chert and mica and every other freaking mineral that lived in this micro-niche but no gold.

  Hold on. What are you looking for again, lady? You’re looking for float. Diorite. Hornfels. That’s what should make your mouth go dry.

  Not gold.

  I glanced at Walter, who was examining a specimen under his hand lens, and then I glanced at Shelburne, who was still in that strange funk on his boulder, staring into the distance.

  They were paying me no attention.

  I recovered my dignity and paid heed to the little pool and riffle pocket where, in my professional opinion, something worth examination might be lodged. Upon closer examination I noticed a ledge. It was recessed, in shadow, and the riffling water was silty, but nevertheless I could make out the shape of a cobble in there. Hard to tell the texture and color but it was worth a closer look.

  I reached.

  My fingers closed on the cobble.

  I yelped.

  I’m not afraid of snakes but for a moment I thought this must be the hump of a coiled water snake, clammy and cold. But if it were a snake it would have moved, would have recoiled from my touch, would have slunk out from the crevice and skedaddled or, worse, and wrapped itself onto my hand and given me a bite. This was no snake. This did not recoil. It simply pushed my fingers aside.

  Walter was suddenly beside me. “Cassie?”

  I let go of the thing and sat back on my haunches. Heart pounding.

  Shelburne sprinted across the gravel bar to flank me on the other side. “What is it?”

  It was a moment before I could speak. “Something’s down there.”

  “What?”

  “It’s not a snake.” I cast about, to explain my reaction. “But it felt...soft. It fit in my hand. About the size of my fist. It felt like...” The word came to me from some primitive zone in a dark corner of my mind. “Like a heart.”

  Shelburne went white.

  I bent back to the water, leaning farther, angling for a better view of the ledge down there, and now I got a straight-on look and saw the thing for what it was. It sat cupped on its ledge in the crevice. I understood my earlier confusion. It was indeed rounded as a river cobble, but not solid. It was big as a heart and it quivered slightly, fanned by the riffling water.

  “Cassie,” Walter said, “what the devil is down there?”

  I straightened. “Mercury.” A quivering heart of liquid mercury.

  Shelburne sucked in a deep breath, let it escape.

  “Well that’s not surprising,” Walter said.

  “It sure surprised me.”

  Walter said, “Millions of pounds were lost from the sluices. You’ll find it in the rivers and soils. You’ll certainly find droplets in catch-basins like this.”

  “Not droplets.” I held my hands apart, to demonstrate the size. A heart.

  His eyebrows lifted.

  I turned to Shelburne. “Did Henry put this here?”

  Shelburne looked taken aback. “Why would he do that?”

  “Why would he leave the dimes? His games.”

  “No no, he didn’t know I’d hired you—at least not until he saw you on the trail with me. And if he did, how would he have time to set this up? And if he did, how could he possibly know you would look down there?”

  I acknowledged the unlikelihood of the scenario but my heart rate had not yet gotten the message.

  “Look,” Shelburne said, “you get enough droplets caught in a hotspot, they coalesce. You can thank Mother Nature for that. I’ve heard of guys finding puddles big as pillows. When my dad brought us here panning, we sucked up mercury with a turkey baster. It’s all the hell over the place.”

  Big as pillows? Holy hell. A heart was big enough for me. I said, “You know a lot about it.”

  “Yes I do. As I’ve explained, Dad marched me and Henry up and down his trail.”

  “Here too?” I asked.

  “Sure. Here.” Shelburne got to his feet. “As you geologists point out, it’s a natural catch-basin. Good place for panning.”

  “Been here recently?”

  “Last time I panned for gold I was twelve years old.” Shelburne started to retreat across the gravel bar.

  “Hang on,” I said. He’d been on edge from the moment the trail brought us here, even before I’d said heart and freaked him out. “Anything else going on here?”

  Shelburne paused. “Like what?”

  “Like whatever’s been making you so edgy.”

  He turned. “Aside from the fact that my brother is missing?”

  “If there’s something else, yeah. Aside from that.”

  A shadow passed over his face. “It’s not relevant.”

  “I would like to be the judge of that,” Walter said. “Before we proceed.”

  Shelburne took a long moment and then he said, “My father died here.”

  Walter and I got to our feet. Scrambling to catch up.

  “This is news,” Walter said.

  “No kidding,” I said, “I thought your father died of a heart attack.”

  “Yes. Here. In fact, it wasn’t the heart attack that killed him. It was falling into the water and drowning.” He grimaced. “Animals got to him before the rangers found him.”

  I flinched. “That’s awful.”

  “Now you understand why this place gives me the creeps.”

  I nodded. That made two of us, now.

  “What was he doing here?” Walter asked. “Panning?”

  “No.”

  “Then?”

  “It’s not relevant.”

  “Indulge me,” Walter said.

  Shelburne shrugged. “He was sampling the water.”

  “Why?”

  “All right.” Shelburne looked at us squarely. “It’s irrelevant but let’s get it out of the way. My father, the auto mechanic, was a handy guy. He developed a piece of technology and brought it to me, looking for funding for a startup. Venture capital, it’s what I do. Dad had a plan to build a super-dredge to suck up mercury, clean up the gold country riverbeds.” He shot me a look. “You saw for yourself what’s down there.”

  I nodded. Seen, and felt.

  “Environmental remediation is the big-bucks term. There’s your new gold rush. Turns out my firm was already working with a deep-pockets company looking to get into the business. So I hooked Dad up with the company, which I’m going to call Deep Pockets. I helped bring the plan to product. I helped Dad come up with a catchy name for his subsidia
ry—AquaHeal. And yes, I came out here with Dad and a Deep Pockets guy a couple of times. Site survey, checking out hotspots, up and down the river. We packed in, stayed awhile.” He held up a hand. “By the way, I did mention my site scouting, earlier.”

  Walter said, evenly, “You didn’t elaborate.”

  “It wasn’t relevant. Don’t know how else I can put that.”

  “It involved your father,” I said. “He died and you found the ore sample and that kicked off what’s going on now.”

  “He wasn’t out here hunting gold when he died. He was here, on his own, taking water samples—as I said. I was in Sacramento trying to get the permit for a second round of tests. Had a few problems with the first round.”

  “What kind of problems?” Walter asked.

  Shelburne sighed. “Dredging is a violent process. It sucks up the riverbed—sediment and gravel along with the mercury. Breaks up large drops into smaller ones.”

  Relevant or not, I flinched. “It floured? Into reactive mercury?”

  “Yes.”

  Jesus. “You’re talking methylation.”

  “Yes. Bacteria convert the inorganic mercury into the nasty form, and that gets into the food chain.”

  I glanced at the river.

  “I wouldn’t eat the fish.” He gave a tight smile. “In fact, you can take that advisory all the way downriver to the San Francisco Bay.”

  I said, “Methylated mercury is a neurotoxin.”

  “Yes. Hence the word problems. Hence the need to tweak the technology. Hence the need for a second round of tests.”

  I shook my head.

  “By the way, storm waters rile up mercury-laden sediments all the time. Mercury gets methylated all the time. It’s already in the state’s water transport system. We just added to the problem.”

  “And Henry?” Walter asked. “Was he involved with the startup?”

  “No, of course not. He had no money to invest, no skills to offer. He’s hardly a company man, anyway.”

  “But he was aware of it?”

  Shelburne shifted. “Actually, no. Henry and I hadn’t been in touch. And then, at Dad’s place, I didn’t bring it up—no point until I knew if the technology would work. As far as Dad goes, he and Henry had nothing to do with one another for years. In any case, once the estate is settled, Henry will inherit half the company.”

  I said, “Did Henry know his dad died here? How he died?”

  “He read the report. Didn’t seem to rattle him. Remember, he spends his life in the wild. Hey, we Shelburnes are hunters. Dad was a hunter. Dad died as he lived, hunting the new gold rush. And he was hunted, in death.” Shelburne put his hand to his neck, as if there were a tie to adjust. “Admittedly, that’s all too wild-kingdom for me.”

  ~ ~ ~

  Walter had moved to sample upstream of the gravel bar when he shouted, “Oh dear.”

  I sprinted across the bar to the rocky bank.

  Shelburne was already sprinting along the bank.

  We joined Walter and looked where he was looking. Into the river.

  The water was clearer here than at the gravel bar. It ran over bedrock and it ran fast and everything on the river bed was glaringly visible. A metal bottle lay on the bottom. It was cylindrical with a screw-cap top lying alongside. It was open. It was rusted. It was about the size of an extra-large water bottle but you wouldn’t want to drink from it. A word came to mind. Flask. In my reading during the drive across the Sierra, I’d come across that word. Heavy iron flasks were needed to hold heavy liquid mercury. Seventy-six pounds of quicksilver per flask.

  A few of those pounds were scattered downstream from the flask, like breadcrumbs. Carried by the fast-moving flow.

  It didn’t take much of a leap to assume that some of the silvery stuff had been carried still farther, until it hit the catch-basin. Until some of it found its way to the hidden ledge, where droplets liked to coalesce.

  I wondered how much of the silver heart was thanks to Mother Nature and how much was thanks to Henry Shelburne. I guessed it didn’t matter.

  Robert Shelburne muttered, “Christ, Henry.”

  Walter spoke. “I suppose one could find flasks abandoned in old mines.”

  I went cold. “You’re saying Henry found a stash?”

  Walter turned to Shelburne. “Is that likely? And if so, how would he transport it? The weight.”

  “Likely, sure. Transport... Rent a horse? Or could’ve lashed it to his backpack. Heavy load but I guess it’s doable.”

  I said, “Why here? It can’t be coincidental that he leaves it here, where your father died.”

  “That’s my brother. Some kind of bizarre memorial.”

  “Is that what you think it is?”

  Shelburne gave a tight smile. “I think it’s preferable to what I thought you’d found, when you shouted.”

  “What did you think I’d found?”

  “My father’s heart.”

  10

  We packed up.

  There was no discussion about continuing, or not continuing. For all its ugliness, the information about Shelburne’s father was not, I had to admit, relevant. The fact that Shelburne’s father died water-sampling on the river where he used to hunt gold was correlative, not causative. The fact that Henry left a memorial or a message was perhaps pertinent, but it was aimed at Robert. Once we found Henry, it was going to become Robert’s predicament. He’d take it from there.

  We set off, following the narrow trail upriver to a place where the water ran free of catch-pools, and because we were low on potable water we decided to stop. We got out our bottles and filtering kits. Shelburne’s pricey model and our bargain squeeze-bag filter both did the job, straining out gut-sickening bugs like Giardia. Either model should in theory filter out microscopic mercury. I would have paid for a filter that put that in writing.

  Resupplied, we moved on.

  The trail again left the river and began to climb. As I plodded uphill I scanned the cliff tops, thinking that if I were Henry Shelburne and I’d been leaving messages for my brother I’d sure want to see his reaction. There were a hundred places to view that site from the cliff tops. But that would take time, to leave the message, to scout the viewpoints. To rent a horse, if he had rented a horse to transport the flask. And it was the question of time that bugged me. Robert Shelburne said his brother left three days ago. If we assumed that Henry was now shadowing us, an assumption that seemed creepily reasonable, then had he abandoned the hunt for the source of the rock? Or had he already found it? Amateur geologist—barely three days in the field if you leave aside travel time from the boarding house to the wild—bam bam bam and he goes straight to the source? I supposed that was possible. This was, after all, his territory.

  Or perhaps he was long gone from the South Yuba, leaving us to our own devices.

  The trail roughened and I abandoned timetables and paid attention to the ground beneath my feet.

  And then our route traversed a gashed canyon gully and we detoured down a spur trail to the river’s gravel bank in order to do some sampling. Small cobbles of quartz and chert chinked underfoot. Of more interest was the fractured bedrock near the river’s edge, which was emplaced with jade-green serpentine.

  Now we were getting somewhere.

  Walter pointed out the rock face. “That’s serpentine. Its soils are associated with gold.”

  Shelburne looked. “That green rock? Never knew I should care.”

  “Good heavens man, it’s the state rock of California.”

  “There’s a state rock?”

  I said, “You’d think the state rock would be gold.”

  Shelburne smiled, as if I’d spoken entirely in jest.

  We moved on, up and over another spiny ridge. Then back down to the river bank, monitoring the cliff tops, watching the sky—how far will we get before we have to make camp, before the rain or the night comes?

  The clouds answered, coalescing to form a seamless roof.

  Hurry
up.

  And then, down another spur trail, at a little pool and riffle system, Walter picked up a large pebble and pursed his lips. He took out his magnifier. He studied the pebble under the twenty-power lens for a good minute, and then he passed the lens and the pebble to me. I had a look. It was black, fine-grained, with the luster of mica and a hackly fracture. It was hard, flinty. I went low-tech, took a steel nail from my pocket and dragged it across the surface. It did not scratch. Its shape was subangular, the edges fairly rounded by transport down the river.

  I nodded and passed it back to Walter because he carried the high-tech tool.

  He already had it out of his pack. The handheld XRF spectrometer looks like a hair dryer but shoots like a gun, firing X-rays at the target, exciting the atoms to display their elemental ID. He laid the pebble on the ground. He put the snout of the XRF to the rock and read the results on the display screen. “Chemically speaking,” he said, “woo-hoo.”

  I said, to Shelburne, “He means that’s a probable match to our hornfels.”

  Shelburne picked up the pebble. Turned it over and over. “There’s no cross.”

  “Could be a question of random chiastolite distribution in the parent rock.”

  Walter said, “She means, we keep going.”

  Thunder sounded, echoing down the canyon.

  We pushed on. We did not have to go far. Ten minutes later, following the bouldery river bank, we hit the mother lode.

  The first angular black pebble I picked up was studded with tiny white crystals that were themselves intruded by black carbonaceous inclusions disposed in the form of a cross. My mouth went dry. Here it was. We’d seen its like in the lab, looking at the angular black chiastolite hornfels embedded in the ore sample. We’d done the geology. We’d set out to find its brother in the field. We’d hypothesized where to find it. And find it we did. Here it was, a little stone in the river. Better than gold.

  I passed it to Walter. He eyeballed it and his face creased into a smile and then he brought out the XRF to confirm. He said, “Woo-hoo, in spades.”

  I said, to Shelburne, “We’ve found the neighborhood.”

  “So where to now?” Shelburne asked.