For William Lisman, the longtime Luzerne County coroner, the first sign of the coming plague appeared in the hills of northeastern Pennsylvania in November 2015.
A 27-year-old woman from one of the mountain towns surrounding Wilkes-Barre was found dead in her family home.
Lisman suspected a drug overdose. She was young. She had been healthy. There were no obvious signs of trauma. And heroin abuse had been on the rise in recent years.
"When a person dies of an overdose, the lungs fill with fluid," he said. "The victims essentially drown in their own fluids."
Because autopsies are expensive and time consuming, many coroners faced with cases like these do toxicological tests designed to pick up traces of known drugs to determine the cause of death. But the first test Lisman administered came back negative. So did the second.
So Lisman listed the cause of death as undetermined.
Several days later, a 34-year-old man was found dead in a sleeping bag in the nearby city of Hazleton.
Once again, Lisman suspected a fatal drug overdose. Once again, the tox tests came back negative. And once again, he listed the cause of death as undetermined.
"I remember when it started because it was budget time and they were about to cut my budget," he said, with a wry chuckle. "At that point the doctor I had been consulting with (about these two cases) told me, 'Bill, there is something going on here'."
Like many coroners in smaller counties, Lisman is not a doctor. But he knows about death. A third-generation Wilkes-Barre resident, he and his family ran a funeral home that buried several generations of city residents. He reached out to fellow coroners in neighboring counties to see if they had similar cases.
They had. And the answer was fentanyl, a powerful painkiller the U.S. Drug Enforcement Administration says is 25 to 50 times more potent than heroin, packs 50 to 100 times more punch than morphine, and can be manufactured easily by illegal drug mills. This was the same drug that killed Prince last April.
"I started hearing about fentanyl and how drug dealers were cutting heroin with it," he said.
Lisman said he had the toxicological tests "tweaked" to detect the presence of fentanyl and "after that, the drug overdoses here skyrocketed."
Facing a crisis, Lisman called the local newspaper, The Times Leader, last May and sounded the alarm.
"I knew I wasn't going to stop people from using, but I wanted people to know what they were using," he said. "This stuff can kill them."
And it has.