AT 3:35 A.M. LAST EASTER SUNDAY, 17-year-old Chuck Borchardt, asleep in a first-floor bedroom of his Jefferson, Wis., home, was jolted awake by a loud bang. A few minutes later, he heard the sound of moaning. When he approached the living room, Borchardt, an experienced hunter, immediately recognized the reek of burnt gunpowder. Following the sound of the moans, he raced to the cellar stairs. Looking down, he saw his father, Ruben, bleeding and slumped across a chair. Shot in the chest and the back, the elder Borchardt, 40, was still conscious. Chuck called 911, then held his father's hand. Before he died, Ruben Borchardt murmured, "I can't believe she would do this to me."

By "she," Chuck believed, Ruben meant his wife, Diane, 45. At first the notion that the study-hall monitor at Jefferson High School would be involved in her husband's murder seemed outlandish to many of the 6,000 residents of this two-stoplight farming town. True, the Borchardts had been going through a divorce, but "Mrs. B," as she was known, was regarded by many students as a sympathetic figure. "She had feelings for everyone," says Jeremy DeBlare, 14, a Jefferson student. "If a kid was crying, she'd cry too." Nonetheless, on Sept. 29, six months after Ruben Borchardt's death, Diane Borchardt was arrested and charged with first-degree intentional homicide. Equally stunning were the arrests of the hit men she had allegedly hired for the killing: Douglas Vest Jr., 17, who was recently voted "the sweetest boy" at Jefferson High; his friend Joshua Yanke, 16, a member of the school choir; and Vest's cousin Michael Maldonado, 15, a high school dropout.

"This is a town where you can walk in the dark without any concerns," says Raymond Krek, Ruben Borchardt's friend and attorney. "That this did happen here, that kids could be hired for murder, is shocking."

Ruben and Diane Borchardt had met on the rebound. In February 1979, Ruben's first wife, Susan, died in a traffic accident, leaving him with two small children—Chuck, who was then a year old, and his sister Brook, 3. Soon afterward, while working as a foreman at Schweiger Industries, a local furniture manufacturer, he began seeing Diane Pfister, a secretary at Schweiger, who was divorced from her first husband. That October, eight months after Susan's death, they married. Their daughter Regen, now 14, was born eight months later.

If there was a honeymoon period, it didn't last long. "I remember in the third grade, when I wished they would get divorced because they were constantly fighting," says Brook, now 19. "She just argued about anything—whether the sky was blue, anything."

Ruben, according to his friends, was quite different. "He'd walk into a room and light it up with his smile," says John Roth, a local utility employee who had been Borchardt's friend since third grade. Says Raymond Krek: "Ruben was very social. Diane was very antisocial—and very anti-Susan. She did everything she could to obliterate the memory of Susan."

At times, in fact, she seemed abnormally possessive of Ruben, who ran a successful cabinetmaking business from their home outside town, and of his children. For as long as she could, Diane tried to hide from Brook and Chuck the fact that Susan was their natural mother. "She was jealous, she wanted us to think she was our real mother," says Brook, who eventually learned the truth from a third-grade classmate. "She would get furious when she even heard I looked like Sue."

For years, say Brook and Chuck, Ruben tried to avoid fights, and for the sake of domestic tranquillity he urged his children to respect Diane. But recently he had begun dating a local woman, a home-maker in her 30s. Diane reacted, say authorities, by asking Jefferson students to spy on the two.

By January 1994, Ruben had filed for divorce and moved into his basement until property and custodial matters could be settled. Diane flatly refused to leave the home that Ruben had built. She also tried to get custody of Chuck, her stepson. Diane became increasingly angry; Ruben, Brook and Chuck all urged her to seek counseling. "Ruben felt she needed help, and he tried to get her help," says his friend John Roth. "She'd turn it around that he needed help."

With divorce impending, quarrels between Ruben and Diane reached such a pitch that Brook moved into a friend's home. Chuck remained at home but says, "Mostly I stayed at a friend's house because I didn't want to be there." More than once, says Brook, Diane threatened her father. Ruben took the threats so seriously, she says, that he would routinely line up empty mayonnaise jars in a hallway leading to a cellar door; it was his makeshift alarm system in case anyone tried to sneak up on him. Diane's anger seemed to increase after Ruben won physical custody of Chuck in a court order and she was told to vacate the house by April 15. Ruben, however, became increasingly cheerful. "Divorce is bad," says Krek, "but it can mean a new life. Ruben had lived in a coffin, and now he was going to get possession of his life."

At Jefferson High, students began to notice a change in Diane. While always capable of being either "real nice or a bitch," as one student put it, she now often seemed depressed. "You could tell she was stressed out last year," said Cory Bloomer, 16, a junior who was in her study hall. "She'd be crying in class, and everyone knew about the divorce."

It was soon after Ruben filed for divorce that Diane allegedly put her plot in motion. In a statement given to police, Doug Vest said she contacted him "three, four or five times," claiming she needed his help to get rid of her husband. She said Ruben had physically abused her, Vest told police. Then, in whispered conversations in study hall, she said she would lose everything in the divorce. "Diane picked on vulnerable children," says one Jefferson student's mother. "Every one of them had a single parent or some problem in their life." Diane also promised money: $20,000 from insurance, plus her wedding and engagement rings and two cars. Almost invariably described as "a nice guy" by fellow students, Vest finally agreed. "I can't explain how he got involved," says his friend Jose Villanueva, 19, a senior. "The money must have looked good to a 16-year-old." According to Vest's police statement, Diane gave him around $600 as a down payment, and he recruited Josh Yanke, whom Villanueva describes as "very shy, a chicken. He stutters a lot when he's scared." Rounding out the teen hit squad was Michael Maldonado, who lived nearby, though authorities say at least one other youth claims Diane asked him to help get rid of her husband.

On April 2, just 13 days before Diane was to move out—and one day before his murder—Ruben Borchardt sensed trouble. "He said, 'Something strange is going on,' " recalls Brook. For one thing, Diane was off visiting Susan's parents some 200 miles away—odd in itself, since the relationship had never been close. Odder still, it seemed from Chuck's testimony, was her taking along Regen and Bugsy, the miniature Schnauzer that Diane had never taken on a trip before and that would bark wildly when anyone entered the house.

According to Vest's police statement, he and Maldonado went to Milwaukee and bought a .410-gauge sawed-off shotgun. On the morning of April 3, Vest said, the three made their way up Bear Hole Road to the Borchardts' 20-acre spread. Failing to break in through the cellar, they got into the house through the first floor. Borchardt, in his undershorts, was coming up the cellar steps when he met the gunmen. At the top of the steps he took one shotgun blast. As he scrambled to get away he took another blast, which knocked him down the stairs. "We were all scared," Vest told police, who were able to crack the case after Maldonado told a friend about his role in the murder.

After Ruben's death, Diane's behavior appeared peculiar to Chuck and Brook. William Hue, their attorney, was struck by how bitterly she complained to him when Susan was mentioned in Ruben's obituary. "People say [her motive] was greed," says Roth, "but I think it was obsession. If she couldn't have him, nobody else could."

While she awaits trial, Diane, with Regen, continues to live in the Borchardt home. She has refused to comment about the case. Chuck, now in the permanent custody of his father's sister Barbara Kulow, has transferred to nearby Lake Mills High School to complete his junior year. Brook, on leave from Madison Area Technical College, is working full-time with the mentally handicapped at a group home in Jefferson.

Meanwhile, Jefferson is bracing for the trials of Diane Borchardt and the three teenage suspects, which are expected to begin next March. Even when legal proceedings are concluded, some fear that Ruben's murder will leave deep and lasting scars. "What made the crime so heinous was that it affected the lives of so many kids," says Krek. "It's unlikely the killers were the only three Diane solicited. It's likely others thought about it for a moment, rejected it and are plagued by the idea 'I almost did the dirts' work. I almost did it.' "

CATHY BREITENBUCHER and BARBARA SANDLER in Jefferson