The drug addict on the Welsh street is at the end of a chain of money, misery, violence and fear; a chain which usually starts across the border in one of the big English cities.
The National Crime Agency estimates there are around 100 so-called "county lines" networks trafficking drugs into Wales, and shipping the money back to the gang bosses.
The operations are run by criminal gangs based in the likes of Liverpool, Birmingham and London which have extended their reach out into smaller towns, cities and coastal resorts around the UK in search of new victims and profits.
With this trade comes antisocial behaviour, crime, violence, and often knives.
This is how the gangs operate.
The gangs
County line operations are run by serious criminal gangs - typically drug dealing may just be one of their enterprises, albeit a lucrative one. Police refer to them as organised crime groups or OCGs. They work through loyalty, violence, and fear. As far as possible the heads of the gangs stay out of the day-to-day business of drugs trafficking.
Below the leaders are a series of trusted operatives who do much of the hands-on work, and are often in charge of the mobile phones that are the key to the operation. They will often also recruit those below them in the hierarchy, as well as sometimes transporting the drugs themselves.
The gang will usually "embed" trusted members in their target towns who will oversee the shipments of drugs, and co-ordinate the onward supply.
The carrying is knives is often routine for those involved in the trade.
Couriers do much of the trafficking of the drugs. Gang members often perform this role but they also recruit, traffic, and exploit vulnerable youngsters - sometimes children - to transport the merchandise. Typically such people will be homeless or having trouble at home, or sometimes they are living in the care system. Often they will be youngsters who have run up debts to the gang, perhaps from their own drug use, or who have "inherited" debts from older siblings.
Once the drugs are in the target town the gang uses a network of local small-time dealers or, at the bottom of the pile, addict street dealers to do the gang's dirty work in return for discounted or free drugs.
The phone lines
The key to the operation are cheap pay-as-you-go mobile phones - often referred to as "burner" phones - and a centralised phone number. This number in effect becomes a "brand" for the gang. Often the numbers will go by the name or nickname of one of the gang such as the "Josh line".
Users can place drugs orders on the number, and members of the gang will also send out bulk texts sometimes to score of contacts at a time advertising their wares, availability, and any special deals they've got. With a number of gangs operating in any given town or city competing for business, drugs have become readily available.
Once the order is placed, dealers are dispatched to make the delivery and collect the cash.
Transporting the drugs
Often vehicles are hired from one of the big national companies, with gangs frequently changing cars in a bid to thwart police intelligence gathering and make the task of tracing them on automatic number plate recognition systems that much more difficult.
It is not uncommon for lower-level courier to just be given a post code to put into a sav nav system and then sent on their way without being told any more details about where they are going.
But gangs also make use of the train and the coach networks to transport their wares, which can make tracking deliveries harder for the authorities.
Usually only small amounts of drugs are carrier on each journey - if the courier is arrested, the loss to the gang is minimised. If they are stopped the trafficker will usually confess to police they are carrying a bit of cannabis and hand it over in the hopes officers won't inquire further.
Often the more valuable consignment of Class A drugs is carried internally by the courier in a technique whose name perhaps means little further explanation is needed - "plugging".
If a gang member is intercepted and is suspected of having plugged drugs, his or her bowel will be closely monitored for the following days - the police's "glass toilet" proecdure.
Cuckooing
The gang will need a base to operate from in their target town. Sometimes they will use a caravan park, hotel, or rented accommodation - but increasingly they use a flat or house belonging to a local addict. The practice is known as "cuckooing" after the bird which famously lays its eggs in another bird's nest.
Drug dealers armed with machete forced man from his Swansea home and into a life on the streets:
A gang will use a combination of the lure of free or discounted drugs, and physical intimidation and sexual violence to effectively move into an addict's property and turn it into a "stash house".
This property will be a base for their operations where consignments of drugs can be delivered to, and from where deliveries to users made. Sometimes the drugs are stored in the flat or house, but increasingly couriers or other gang members lower down the chain are used as human storage vessels, and keep the drugs hidden internally.
The addicts
At the bottom of the chain are the addicts, the ready market for the goods the dealers are peddling. Addicts will fund their habit through acquisitive crimes such as burglary, shoplifting, or theft from cars. Female addicts sometimes turn to the prostitution. An addiction can cost hundreds of pounds of week to feed.
Such is the influx of gangs with goods to sell, addicts often find themselves bombarded with text messages offering drugs .
Between 2000 and 2016 the number of deaths in Wales where opioids were mentioned on the death certificate almost tripled 58 from to 158.
How lucrative is it?
The short and unpalatable truth is - very. Some gangs are estimated to earn thousands of pounds a day from dealing in Class A drugs in Welsh town and cities. Though large amounts of cash go through the hands of those dealing on the ground, the money is quickly passed up the chain of command to those at the top.
Often these profits from misery are used to fund the gang's other criminal enterprises.
The police response
Recent years have seen a number of major police investigations which have smashed county lines gangs.
In 2018 police in Swansea dismantled a gang drug trafficking network which eventually led to 46 people being sentenced to more than 180 years in prison. As part of operation Blue Thames undercover police officers immersed themselves in the city's drugs community .
This year in Cardiff more than 100 people have been arrested, and drugs, cash and knives sized by police as part of Operation Crater.
Meanwhile just before Christmas members of a large-scale conspiracy targeting Powys were sentenced to 100 years as part of Dyfed-Powys Police's Operation Regent.
But with no sign of a decrease in the demand for drugs on the streets of Wales, is unlikely we have seen the last of such investigations.
