Police believe the same man is behind a string of unsolved cases in Hickory.
Someone is targeting restaurants at closing time and holding employees at gunpoint during those robberies, according to police.
Police said he is surprising workers as they head to their cars at night.
The robbery at Wendy's on Friday morning was the fourth case this month.
The door workers said they came out around 2 a.m. when the robber came out of some bushes with a gun in his hand.
Police said like the other cases at a Burger King and a Tripps restaurant, he forced the employees back inside at gunpoint and then ordered them to open a safe.
In the most recent robbery, there were four employees, and they did what police have been encouraging restaurant workers to do -- leave as a group.
But Roger O'Neil, who works at the restaurant, said that didn't help in this case, and it was clear this robber meant business by what he was saying.
"He said that if we thought it was a fake gun that he would show us that it wasn't. That he wanted us to all follow what he was saying or else he would kill us. He was like, he didn't want to kill anybody tonight, but he will," O'Neil said.
Police said they have only a vague description of a man of slight build, 5 feet 7 inches tall, weighing about 145 pounds. Anyone with information on the case is asked to give police a call.