Just outside Knoxville, Tennessee, a university-issue white Ford pickup truck cuts diagonally across the nearly empty parking lot behind the University Medical Center and pulls to a stop in front of a chain-link gate. A car door opens, and out bounds Dr. William Bass, a burly man, solid and fit for his 71 years. He has close-cropped gray hair, oversized glasses, gray tweed jacket, white button-down shirt. On the ring that holds the keys to his truck, house, and office are the keys to the University of Tennessee Anthropology Research Facility, known to the locals by a more familiar name: the Body Farm.

Cars pull into other spots in the lot. Doctors, nurses, and medical students walk briskly to morning classes without so much as a glance toward the fence that rings the Farm. It's two fences, really: The outside fence is chain-link, six feet high, with $2,000 worth of fresh razor wire tangled along its top. That fence is backed by a wooden "modesty" fence similar to one that might separate your backyard from your neighbor's--except that this barrier hides three acres unlike any others in the world.

Bass, a forensic anthropologist by training, began his career in the classroom, but over time began to help police departments across the United States identify bodies. He learned a lot from examining bodies at crime scenes, and setting up an outdoor laboratory where he could conduct experiments on human bodies left to weather the elements was a natural extension of his work. Eventually he'd be able to tell law enforcement agencies more about the bodies they discovered. Thus, in 1971, the Body Farm was born.

The gates swing open, and we walk into a clearing the size of a backyard, ringed by thick underbrush and a stand of vine-covered trees. Crossing the threshold snaps the senses to a state of full awareness; it's like passing through an invisible wall that keeps two worlds apart. The smell is noticeable, but it's more stale than wretched. I see an old mailbox, a few cardboard boxes, a couple of old rusting cars, a ladder, and some shovels leaning up against the fence. And the dead bodies. About a dozen are in plain view, stretched out on the ground. Most are covered by thick black plastic tarps or white cotton bedsheets. Each body wears two bright orange plastic tags, strapped to arm and ankle. Next to each body is a small metal sign that, like the orange tags, identifies the body by code. "WM 43 2/97" translates as "white male, 43 years old, the second body placed at the Farm in 1997." Names and personal histories are kept in a locked file cabinet in Bass' office.

Many people stipulate in their wills that their bodies be donated to science. Few of them are likely to have in mind Bass' field of study, a little-discussed area of forensic science. The bodies are first used by forensic science students; eventually, the bones are turned over to the anthropology department for further study. In this way, the Body Farm makes scientific sense, just like the organ donor checkoff on your driver's license. It's the intersection of science and emotion that's a bit hard to get around.