A heroin user prepares to inject himself. Communities nationwide are struggling with the unprecidented heroin and opioid pain pill epidemic. (John Moore/Getty Images)

At the retail end of the global heroin trade, local heroin rings repackage pounds of the drug into single-serve doses and push the product to its final destination: the user. From there, the next stop is often a hospital emergency room or a morgue, as an epidemic of heroin-related overdoses and deaths continues its creep across the country.

In Virginia, an intensive crackdown on heroin rings has shed new light on the relationship between drug dealer and user, providing insight into why that last link in the heroin trafficking chain has become so deadly.

“What we hear from users is that quality is important, and that the reputation of a dealer is rated on a scale of one to 10,” said Marc Birnbaum, assistant attorney general for Virginia.

In a competition for higher ratings, some dealers began offering heroin with varying potencies — from just strong enough to stave off withdrawal symptoms to doses laced with powerful synthetic opioids such as fentanyl.

“We’ve talked to users whose dealers will say, ‘I got the stuff that will keep you from getting sick, and I got the stuff that will kill you,’ ” Birnbaum said. “It’s a tragic situation because, for the most part, they want the most potent dose.”

For some heroin addicts, word of a drug overdose is an indication of a high-quality product. For the dealer, the overdose can serve as advertising. Such is the perversity of the heroin trade that a dealer’s customer base can grow because the product kills customers.

Birnbaum, who handles drug trafficking cases in Northern Virginia, is part of a statewide heroin trafficking task force set up three years ago by Virginia Attorney General Mark R. Herring. The crackdown was in response to a public health crisis: According to the Office of the Chief Medical Examiner, heroin overdoses among whites in Virginia increased by 46 percent between 2010 and 2015. Among African Americans, the rate was an alarming 165 percent.

In just the first nine months of 2016, there were 400 fentanyl-related deaths in the state.

So far, Herring’s efforts to break up heroin rings have resulted in 79 arrests and the seizure of 375 pounds of heroin. That amount could yield 1,690,000 individual, 0.1-gram doses cumulatively worth $16 million, according to state law enforcement officials.

That’s a lot of heroin.

Still, hundreds of tons of the drug are smuggled into the United States each year. For about $80,000, a local drug ring can purchase a kilogram of heroin (2.2 pounds) and, after mixing it with synthetic opioids, earn a half-million dollars from individual sales.

In the face of such high profits and huge supply, Herring has also developed drug awareness programs aimed at youth and their parents. But reducing demand for drugs can be just as challenging as stopping the supply. Once a user gets hooked on heroin, it virtually sells itself.

“What we often see are individuals who have a drug connection, who are users, drive from Fairfax County into the District or Prince George’s County and sometimes up to Baltimore to buy heroin for themselves or on behalf of others,” Birnbaum said.

Emylee Lonczak, a 16-year-old student at McLean High School, was one of those who made such a trip. In 2013, she and a friend drove from Fairfax County into the District to buy heroin from a dealer named Antowan Thorne. The girl later died of an adverse reaction to a mix of heroin and antihistamines.

Thorne was charged with conspiracy to distribute heroin. At his trial, a woman testified for the prosecution that she had met Thorne in a crack house when she was 15, and that he was selling drugs to minors.

Thorne was convicted and sentenced to 25 years in prison.

Not long afterward, Birnbaum prosecuted another case in which a dealer sold heroin to someone who overdosed and died. The dealer was the same woman who testified against Thorne.

“It just shows that once people go down that road to using, it can be so difficult to escape even if that person has an absolute desire to do so,” Birnbaum said.

At a news conference last month, Herring announced the arrest of 11 people alleged to have been members of an Alexandria-based drug ring. The heroin haul from that bust was just over 400 grams, and prosecutors said the group had handled more than a kilogram over the past year.

“Lives will be saved because they are no longer dealing,” Herring said, optimistically. Then, speaking more realistically, he added, “We’re not going to be able to arrest our way out of this problem.”

Drug dealers know you can’t OD your way out. Addicts don’t always want a way out. Families can’t bargain or cry their way out.

But there has to be a way.

To read previous columns, go to washingtonpost.com/milloy.