For a group of friends, the terror of the Nashville Nightmare Halloween attraction became a gruesome reality when one of them stabbed another with a real knife.

As they were waiting to head into the venue around 9 p.m. Friday, an unknown person who the group believed worked for the attraction approached the group of four friends, according to a report from the Metropolitan Nashville Police Department.

The stranger, who the group believed to be a character actor, asked one friend if another was “f–king around with her,” according to the police report. She told police she thought the person was “playing around” and said yes.

Then, the person handed her a knife which the group believed to be a prop from the attraction. At the person’s instruction, the friend “stabbed at the victim.”

“As she pulled back, she realized that there was blood on the knife, there was a hole in the victims’ shirt and blood was squirting from the victim’s left arm,” the incident report said.

The unknown person took the knife back, the friends told police.

The other two friends and the one who was injured told police they did not believe their friend had any intention to harm them. They said they all believed the stranger to be part of the attraction and thought the knife was fake.

The woman has not been charged with a crime, a police spokesperson confirmed to Fox News.

The victim was transported to a hospital and treated for a “severe laceration” on his arm.

The other unknown suspect was described as a skinny male who wore skull face makeup and a straw hat with a striped band, according to the police report.

For Friday the 13th in July, Nashville Nightmare hosted an event called “Slasher Fest.”

Neither Nashville Nightmare nor Thirteenth Floor Entertainment Group responded to a request for comment by Tuesday afternoon.