In a disturbing lesson about not talking to strangers, a six-year-old boy was forced to endure four terrifying hours of being "kidnapped" by his family members. The boy's mother, aunt, and grandmother allegedly conspired with a gas station employee to abduct the child, hold him at gunpoint, and threaten to sell him into sex slavery.

According to the St. Louis Dispatch, Denise Kroutil, the boy's aunt, enlisted the help of Nathan Firoved, 23, whom she worked with at a gas station. Firoved, police say, lured the boy into his pickup truck on his walk home from school this past Monday. He allegedly told the boy he would "never see his mommy again" and that he was going to be "nailed to the wall of a shed." The horrifying story goes on:

As the boy started to cry, Firoved showed him a handgun and told the child if he didn't stop crying he would hurt him, authorities said.

Firoved continued driving the boy around in his truck, then because he would not stop crying, Firoved bound the boy's hands and feet with plastic bags and covered his face with an adult-sized jacket so he couldn't see, police said.

Later, Firoved took the boy — still blindfolded — to the basement of the boy's home and left him there, authorities said. The boy's aunt, Kroutil, removed his pants and told him he could be sold into "sex slavery." She also chastised him because he did not try to resist her. He did not recognize her voice.

The boy's grandmother, Rose Brewer, apparently listened in on the events transpiring in the basement with a baby monitor.

After being kept in the basement of his home for "an undetermined amount of time," authorities say, the boy's restraints were removed and he was told to go upstairs, where his family "lectured him about staying away from strangers."

The four involved in the plot were arrested by Lincoln County, Mo. police Wednesday after the boy told the story of his "lesson" at school.

"They have no idea that what they've done is outside boundaries of law," Lt. Andy Binder with the Lincoln County Sheriff's Office told KMOV.

The boy has since been placed in protective custody. Firoved, Kroutil, and Brewer were charged by police with felony kidnapping, felonious restraint, and felony abuse and neglect of a child; his mother, Elizabeth Hupp, was charged with felony kidnapping and felony abuse and neglect of a child.

[Clockwise from top left: Elizabeth Hupp, Nathan Firoved, Denise Kroutil, Rose Brewer // Image via Lincoln County police]