On midnight of the occult holiday known as St. Agnes's Eve, when the clouds were low over Hendricks County and scuttling through the sky in a buffeting wind, Lt. Michael Nelson, 39, churchgoer and family man, drove the back roads in an unmarked police car. Scanning isolated churches and abandoned graveyards, he was looking for satanic ceremonies, hoping to find a clue as to why bodies seem to be disappearing from this corner of rural Indiana even faster than working farms.

Turning into an unlighted, muddy lane, he extinguished the headlights. Ahead of him was a copse where dog bones and candle drippings were found in September, suggesting a ritual mutilation. To his right was the 19th-century Weaver-Dillon graveyard, obscured by brush, where one adult grave was found empty and two infant graves were disturbed last year. A faint, eerie whine carried across the tangled woods, and the air smelled of fresh, damp earth.

Nelson took a light-enhancing night scope from a case and scanned the fields. No cult festivities were evident this night, and as the wind died it became apparent that the whine was coming from tractor trailers roaring by at ungodly speeds on nearby Interstate 74. The smell of fresh earth emanated from fertile cornfields, not spades reaching into hoary graves. Pulling back onto the blacktop, Nelson headed toward an old house once inhabited by a woman who decapitated her girlfriend. In the past year robed revelers were spotted on the property. "Frankly," said Nelson, a modern lawman hunting evildoers from a more primitive age, "this investigation scares the hell out of me."

He began his inquiries in September, when a tip came into the Hendricks County sheriff's office that a body had been taken from a rural graveyard called Hadley Yards. Once his investigation became public knowledge, other excavations were reported. It soon appeared that ever since 1986, grave robbers had been working Hendricks County as industriously as door-to-door Bible salesmen did in more orthodox days.

Within the county's 417 square miles are 126 recorded graveyards, most of them family plots. Not all the graveyards have been checked, so difficult are many of them to reach, but at least six of the oldest burial places have been dug into and, according to Nelson, the bones of as many as 15 adults have been removed. No witnesses have come forward. The only known living descendant of a suspected victim is Hugh Weaver, 72, a distant relative of Abia Dillon, whose grave was found empty last year. "It's just not very nice to think about," said Weaver, who refused even to look into the empty hole where Abia once lay. "I didn't have the guts."

Whoever may be carrying off the remains of the county's early settlers is surely not part of the mainstream of Hendricks County, which Sheriff Roy Waddell, 49, describes as "basically a rural, well-to-do, conservative, bedroom community." Located just a few miles west of Indianapolis, the county is mostly corn and soybean fields, peeling barns, tired farmhouses and spiffy commuter subdivisions.

Nelson suspected that the grave robbers might be looking for jewelry until he decided that jewel thieves would not carry off entire skeletons. He considered other explanations, including a black market in bones for medical schools, but realized schools would prefer fresher specimens. Finally he set out to educate himself about the occult. From his readings, which constitute a best-seller list of the bizarre, he learned that some religious cults prize old human bones, believing the spirits of the deceased reside in them, and that some value the dirt from the graves of unbaptized infants.

Nelson's hunch, however, was that the grave robbers were involved in satanic worship, and these suspicions were corroborated by a former cult priestess who agreed to an interview with him. (She now has a desk job instead of a cult position—the pay is better, the hours regular, and she no longer has to fornicate with barnyard animals.) "Satanic cults are the only thing that makes sense to me," the woman told him after hearing the evidence. "If they took an entire skeleton, they might cremate it in a sacrificial manner." She recommended that Nelson look for these ceremonies at abandoned or little-used churches, particularly on occult holidays, and assured him that he would have little difficulty identifying the participants: They would be wearing robes or frolicking in the nude. "This is not a traditional investigation," Nelson sighed.

Nelson's wife, Phyllis, 41, a former sergeant with the Indianapolis airport police, now working for a private security firm, supports his belief that Satanic cult members are robbing graves. Nelson's superiors are not convinced. Recently the sheriff ordered him back in uniform and placed him on a patrol shift, in effect ending the investigation until new information is forthcoming.

Sheriff Waddell has been playing devil's advocate in Nelson's investigation. He points out there is nothing but a few deep holes to suggest that bodies have been disturbed. He also notes that in the 28 years he has lived in Hendricks County, he has never seen a sign of satanic activity, and he hates the idea that outsiders might think the place is "full of devil worshipers." Asked how long a visitor would have to hang around in order to see such local color, Sheriff Waddell replied, a little coolly, "Probably forever."

In fact, evidence of satanic activity in the county seems to exist largely in the imagination—or at least in the assumptions—of the beholder. Years ago, recalls Nelson, he drove up to an isolated house outside the town of Brownsburg and observed people standing around a bonfire on a snowy night. When he approached in his marked car, the group scattered. He won't go so far as to say that this was a satanic gathering, but he will say this: "It wasn't a wienie roast."

John Roof, chaplain of the sheriff's department and rector of a local Episcopal church, doesn't think the grave robbings amount to more than a prank—"That's as much attention as I pay to it," he says—but he conceded that about 15 years ago some sacramental vessels were stolen from an Episcopal church and recovered in an unoccupied house decorated with satanic symbols. There have also been reports in the county of animal mutilations involving the dismembering of cats and squirrels.

A number of citizens, the sheriff among them, think the culprits might be kids, not cults, though Nelson insists otherwise. "This is not a gag or a prank," he said. If youngsters are at work, they are probably the ones who practice perfect penmanship and keep their desks neat in school because most of the graveyard excavations have been meticulous jobs. Nancy Petercheff, 66, who discovered two emptied graves on her farm, said, "Somebody worked hard, and somebody knew how to do it."

Whoever these somebodies are, they are having a wicked effect on the home life of the Nelsons, for Phyllis and Michael do not sleep nearly as well as they did before the investigation started. About a month ago Phyllis woke up in the middle of the night and said to Michael, "Do you hear that? It's a man moaning." He didn't hear a thing, but that didn't mean he was enjoying a restful night. "I read before I go to bed, different subjects that might apply to the case, and I think that's the wrong thing to do," he said. "What I read about, I dream about. One night I woke up thinking they'd gotten me."

Nelson believes that if he can proceed with the investigation, modern police methods will prevail over those who live by superstition and depravity. If the price he must pay is not resting easily, he knows that Abia Dillon, David and Joanna Stout and the others who may have been taken from their graves are no longer resting at all.