“Forceps,” she said, holding out her hand. Yoshima placed the instrument in her palm.

“You see it?” asked Jane.

“Yes.”

Maura snagged the object and gently withdrew it from the throat. She dropped it onto a specimen tray, and it clattered against stainless steel.

“Is that what I think it is?” said Jane.

Maura turned over the specimen, and it gleamed like a pearl under the bright lights.

A seashell.

The afternoon light had darkened to a somber gray by the time Jane drove onto the Harvard University campus and parked her car behind Conant Hall. The lot was nearly empty, and as she stepped out into a bitter wind, she glanced at old brick buildings that looked deserted, at fine feathers of snow swirling across frozen pavement, and she realized that by the time she finished her task here, it would be dark.

Eve Kassovitz was a cop, too. Yet she never saw death coming.

Jane buttoned up her coat collar and started toward the University Museum buildings. In a few days, when students returned from winter break, the campus would come alive again. But on this cold afternoon, Jane walked alone, eyes narrowed against the wind’s bite. She reached the side entrance to the museum and found the door locked. No surprise; it was a Sunday afternoon. She circled around to the front, trudging a shoveled path between banks of dirty snow. At the Oxford Street entrance she paused to stare up at the massive brick building. The words above the doorway read, MUSEUM OF COMPARATIVE ZOOLOGY.

She climbed the granite stairs and stepped into the building, and into a different era. Wood floors creaked beneath her feet. She smelled the dust of many decades and the heat of ancient radiators, and saw row after row of wooden display cabinets.

But no people. The entrance hall was deserted.

She walked deeper into the building, past glass-enclosed specimen cases, and paused to stare at a collection of insects mounted on pins. She saw monstrous black beetles with pincers poised to nip tender skin, and winged roaches, carapaces gleaming. With a shudder she walked on, past butterflies bright as jewels, past a cabinet with birds’ eggs that would never hatch, and mounted finches that would never again sing.

The creak of a footstep told her she was not alone.

She turned and stared up the narrow aisle between two tall cabinets. Backlit by the wintry light glowing through the window, the man was just a bent and faceless silhouette shuffling toward her. Only as he moved closer, emerging at last from his dusty hiding place, did she see the creased face, the wire-rim spectacles. Distorted blue eyes peered at her through thick lenses.

“You wouldn’t be that woman from the police, would you?” he asked.

“Dr. Von Schiller? I’m Detective Rizzoli.”

“I knew you had to be. No one else would wander in this late in the day. The door’s normally locked by now, so you’re getting a bit of a private tour here.” He gave a wink, as though this special treat should stay a secret between them. A rare chance to ogle dead bugs and stuffed birds without the hordes pressing in. “Well, did you bring it?” he asked.

“I’ve got it right here.” She removed the evidence bag from her pocket, and his eyes lit up at the sight of the contents, visible through the clear plastic.

“Come, on, then! Let’s go up to my office where I can get a good look at it under my magnifier. My eyes aren’t so good anymore. I hate the fluorescent lamp up there, but I do need it for something like this.”

She followed him toward the stairwell, matching her pace to his agonizingly slow shuffle. Could this guy still be teaching? He seemed far too old to even make it up the stairs. But Von Schiller was the name recommended to her when she’d called the comparative zoology department, and there was no mistaking the gleam of excitement in his eyes when he’d spotted what she had brought in her pocket. He could not wait to get his hands on it.

“Do you know much about seashells, Detective?” Von Schiller asked as he slowly climbed the stairs, his gnarled hand grasping the carved banister.

“Only what I’ve learned from eating clams.”

“You mean you’ve never collected them?” He glanced back. “Did you know Robert Louis Stevenson once said, ‘It is perhaps a more fortunate destiny to have a taste for collecting shells than to be born a millionaire’?”

“Did he, now?” I think I’d rather be a millionaire.

“It’s a passion I’ve had since I was a child. My parents would take us every year to the Amalfi Coast. My bedroom was filled with so many boxes of shells I could barely turn around. I still have them all, you know. Including a lovely specimen of Epitonium celesti. Rather rare. I bought it when I was twelve, and paid quite a dear price for it. But I’ve always thought that spending money on shells is an investment. The most exquisite art of Mother Nature.”

“Did you get a look at the photos I e-mailed you?”

“Oh, yes. I forwarded the photo to Stefano Rufini, an old friend of mine. Consults for a company called Medshells. They locate rare specimens from around the world and sell them to wealthy collectors. He and I agree about your shell’s probable origins.”

“So what is this shell?”

Von Schiller glanced back at her with a smile. “You think I’d give you a final answer without actually examining it?”

“You seem to know already.”

“I’ve narrowed it down, that’s all I can tell you.” He resumed climbing the stairs. “Its class is Gastropoda,” he said. Climbed another step. “Order: Caenogastropoda.” Another step, another chant. “Superfamily: Buccinacea.”

“Excuse me. What does all that mean?”

“It means that your little seashell is, first of all, a gastropod, which translates to stomach foot. It’s the same general class of mollusk as a land snail or a limpet. They’re univalves, with a muscular foot.”

“That’s the name of this shell?”

“No, that’s just the phylogenetic class. There are at least fifty thousand different varieties of gastropods around the world, and not all of them are ocean dwellers. The common land slug, for instance, is a gastropod, even though it has no shell.” He reached the top of the stairs and led the way through a hall with yet more display cases containing a silent menagerie of creatures, their glassy eyes staring back at Jane in disapproval. So vivid was her impression of being watched that she paused and glanced back at the deserted gallery, at cabinet after cabinet of mounted specimens.

Nobody here but us murdered animals.

She turned to follow Von Schiller.

He had vanished.

For a moment she stood alone in that vast gallery, hearing only the thump of her own heartbeat, feeling the hostile gazes of those countless creatures trapped behind glass. “Dr. Von Schiller?” she called, and her voice seemed to echo through hall after hall.

His head popped out from behind a cabinet. “Well, aren’t you coming?” he asked. “My office is right here.”

Office was too grand a word for the space he occupied. A door with the plaque-DR. HENRY VON SCHILLER, PROFESSOR EMERITUS-led to a windowless nook scarcely larger than a broom closet. Crammed inside were a desk, two chairs, and little else. He flipped on the wall switch and squinted in the harsh fluorescent glare.

“Let’s see it, then,” he said, and eagerly snatched the ziplock bag that she held out to him. “You say you found this at a crime scene?”

She hesitated, then said, merely, yes. Rammed down the throat of a dead woman was what she didn’t say.

“Why do you think it’s significant?”

“I’m hoping you can tell me.”

“May I handle it?”

“If you really need to.”

He opened the bag and, with arthritic fingers, he removed the seashell. “Oh yes,” he murmured as he squeezed behind his desk and settled into a creaking chair. He turned on a gooseneck lamp and pulled out a magnifying glass and a ruler. “Yes, it’s what I thought. Looks like about, oh, twenty-one millimeters long. Not a particularly nice specimen. These striations aren’t all that pretty, and it’s got a few chips here, you see? Could be an old shell that’s been tumbled around in some hobbyist’s collection box.” He looked up, blue eyes watery behind spectacles. “Pisania maculosa.”