It starts with text messages.
Hundreds of them, sent from the one phone, beamed out to 'customers' every morning to advise them of the crack cocaine and heroin deals on offer for the day.
In Harrogate, about 200 to 250 daily drug users will receive the messages and respond accordingly, as the phone's operator sets up a day packed with illicit business.
The operator themself isn't in Harrogate though, or even Yorkshire - they're based in Manchester, and that's where the unique elements of "county lines" crime come in.
The operator has 'befriended' a 16-year-old boy, with the aim of recruiting him into his drug-dealing network.
The boy will typically come from a background that has left him vulnerable and socially isolated. There's a high chance he comes from a single-parent family, or his parents may be drug users too.
Showered with money or gifts and vulnerable to the influences of social media posts glamorising drug-dealing, the boy is loaded up with a backpack carrying between 150-200 'wraps' - packages of heroin or crack cocaine.
In another potentially deadly twist, there's a good chance he'll also be armed with a knife or a machete.
He'll catch the train by himself from Manchester to Harrogate or another North Yorkshire town, before spending the day distributing drugs to the 'customers' reached by that morning's text messages.
The above story is given as a classic example of the county lines model by North Yorkshire Police's Temporary Detective Sergeant Tom Barker - one of a seven-strong team tasked with tackling county lines crime in Harrogate.
Eventually, when the operator has enough trust in his young sidekick, he'll be told to take 500 wraps with him and spend the week in Harrogate, commandeering the house of a regular customer to live and deal from - an action described by police as 'cuckooing'.
"Typically, end users are quite happy to have host a young drug dealer, as it means they'll get free drugs," Detective Sergeant Barker said.
It's a lifestyle that opens up young people to a variety of abuses - particularly physical and sexual - and is why Detective Sergeant Barker says it's so important to smash the lines and childrens' involvement in them.
Rather than catching and charging young people, Detective Sergeant Barker said it's about knowing the signs of when a young person is at risk, and preventing them from progressing down the wrong path.
"For me, it's a lot more about education," he said.
Lachlan Leeming, Local Democracy Reporter