The cop straightened upon seeing us.

“Dr. Temperance Brennan.” I flashed my LSJML security card as Ryan badged him. “Rodas requested our presence.”

The guy barely glanced at our IDs. From another room, I heard the sound of drawers opening and closing. “He’s in the big shed out back.”

“Thanks.”

“Tight security,” Ryan said when we’d rounded the corner of the house.

“It’s rural Vermont.”

We followed the path up the hill. Added ours to dozens of boot prints in the half-frozen muck.

The shack was made of unpainted boards barely maintaining contact. The roof was rusted tin, louvered at the top, curling free of the nails securing it at the bottom.

The shed’s two barnlike doors were thrown wide, and its interior was visible in bright detail. The scene looked surreal, like a movie set lit by an overzealous gaffer. I assumed portable lights had been brought in and set up.

Set up for what?

In a far corner, partly in shadow, two figures stood talking beside a blue plastic barrel. One was Umpie Rodas. The other was a tall woman with a red knit hat pulled low to her brows. A full-length black coat obscured her shape. Both turned at the sound of our footsteps. Rodas was hatless, and his jacket was unzipped. He may have had on the same red shirt he’d worn in Charlotte. Or maybe he had a collection.

“Glad you made it. Sorry about the weather.”

Ryan and I entered. The shack smelled of smoke, moist earth, and something sweet, like a pancake house on a Sunday morning.

I was right about the lights. There were three, the standard tripod variety often used at crime scenes. The generator was gas-powered, the kind you can buy at any Home Depot.

Rodas made introductions. The woman, Cheri Karras, was with the chief ME’s office in Burlington. Instead of mittens, she wore surgical gloves. So did Rodas.

I felt a knot begin to form in my gut.

Behind Karras, a man in a thick padded jacket was snapping photographs. His breath glowed white each time his flash went off.

I took a quick look around. The floor was hard-packed dirt, filled with a hodgepodge of items. Enormous cauldrons, blackened by fire. An open box containing blue plastic bags. Beside it, dozens of identical boxes, unopened. Circling the walls, rusty buckets, saucepans of differing sizes, screens, juice and milk cartons, five-gallon white plastic tubs stacked to form wobbly five-foot towers.

Crude shelving held wooden boxes filled with small metal implements that had a spike at one end and a downspout opposite. Others held metal hooks. Two drills. An assortment of hammers. A half-dozen coils of blue tubing. Jugs of household bleach.

At the shack’s center, directly below the vented part of the roof, was a three-by-five brick-lined pit with iron bars running between the long sides. On the bars sat a rectangular flat-bottomed metal pan, empty, its interior yellowed by some sort of residue. The bricks and bars were fire-blackened and covered with soot. Ditto the outside of the pan.

I was stumped. But one thing was clear. Whatever the shed’s purpose, cobwebs and grime suggested years of disuse.

“—got word no one was occupying the property, I decided to take a look around, be sure vandals weren’t up to mischief. We get squatters sometimes, folks find an empty summer home, decide to move in for the winter.”

My attention refocused. On Rodas. On Karras. On the ominous blue barrel between them.

“House had been breached, all right. Lock was jimmied. That was my green light. No damage inside, nothing worth stealing, so I took a peek out here.”

“Cabane à sucre.” For some reason, Ryan said it in French.

Of course. The shed was a sugar shack, a place to convert maple sap into syrup.

I eyed the barrel. The knot tightened.

Rodas nodded. “A Quebecer would know, eh?”

Karras’s phone buzzed. Wordlessly, she stepped outside. I watched her as Rodas continued talking. She seemed untroubled. A raccoon in the barrel? Or just another day with death?

“The property’s deeded to Margaux and Martin Corneau. Ten acres, eight of ’em mixed red and sugar maple. Until the late ’80s, the Corneaus ran a small operation, provided ten, twenty gallons a year to an outfit that bottled and sold locally.” Rodas arced an arm at the paraphernalia around us. “The old stuff’s theirs, cauldrons, aluminum buckets and lids. The plastic collection bags and polyethylene tubing, now, that’s something else.”

“Meaning?” Ryan asked.

“Meaning they’re new.”

“Suggesting a more recent operation.”

Rodas nodded, his expression grim. But something else. Excited? Eager?

“By whom?” Ryan asked.

“I’m working on that.”

“What’s in the barrel?” Not trying very hard to hide my impatience.

“We’d best wait for Doc Karras.”

“Where do you buy sugaring equipment?” Ryan asked.

“Anywhere. The barrels are widely used for food storage. The tubing’s multipurpose.”

“The taps and bags?”

“Sugaring supply companies. The capture bags aren’t expensive, maybe forty cents each. Most small producers now prefer them to buckets. Slip the bag over a collar, run the tubing straight in from the tap, empty the sap into a collecting point, toss the bag, repeat until the tree runs dry. Bags are also better at keeping out bugs and debris.”

“Can’t be that many sold.”

“More than you’d think.”

“Can you purchase them online?”

Rodas nodded. “Got someone making calls.”

Karras was still on her phone.

I wrapped my arms around my torso, hands tucked under my armpits for warmth. Cold was rising through the soles of my boots and spreading through my bones. The chill coming from more than the weather.

“That an evaporator?” Ryan chin-cocked the fire pit.

“Yeah. Better than the cauldrons, but still takes a lot of fuel.”

“Seriously?” I snapped. “We’re discussing advances in the art of syrup production?”

“The woodshed’s beside this one.” Rodas ignored my outburst. “Not much left. I suspect the neighbors helped themselves over the years.” Turning to me. “You know much about maple syrup?”

“We’re wasting time here.” Rude, but I was freezing. And anxious. And fed up with the male-bonding routine.

“Then let’s use it to learn something.” Rodas took my nonresponse as invitation to continue. “During the growing season, starch accumulates in the roots and trunks of maples. Enzymes transform the starch into sugar, then water absorbed through the roots turns it into sap.

“In the spring, alternating freezes and thaws force the sap up. Most folks tap once daytime highs hit the forties. Around here, that’s usually late April.

“The sap then has to be processed to evaporate out the water and leave just the concentrated syrup. That means boiling between five and thirteen gallons of sap down to a quarter of a gallon of syrup. You can do that entirely over one heat source.” Rodas gestured at the fire pit. “Or you can draw off smaller batches as you go, and boil them in pots.” Pointing at the pots.

“Is this really relevant?”

Rodas grinned at me. “You need some coffee? I have a thermos.”

“I’m good.” Curt.

“The bottom line is, maple syrup is roughly sixty-six percent sugar. Just sucrose and water, with small amounts of glucose and fructose created during the boiling process. Some organic acids, malic, for example. A relatively low mineral content, mostly potassium and calcium, some zinc and manganese. A variety of volatile organic compounds, vanillin, hydroxybutanone, propionaldehyde.”

“Hallelujah. A chemistry lesson.” I wasn’t believing this.

“Sucrose, glucose, and fructose. Gooey and sweet. That bring anything to mind?”

Holy shit. I got it.

Before I could respond, Rodas’s eyes went past me toward the open doors. As I turned, Karras stepped into the light. Droplets glistened on her shoulders and hat.