In 2013, a Canadian father-of-three made contact with a 13-year old Irish girl on a website that allows people to connect randomly with other users.
Their encounter on the website was described as "random" - but was the beginning of a nightmare for the young girl and her family.
Some 14 months later, Jashua Tremblay, then aged 30, crossed seven time zones to spend a week with his victim, having sex with her after bringing her to a hotel.
That trip would be the first of two predator Tremblay, from Alberta, Canada, would make to Ireland to meet with his victim.
In that time he had convinced the teenager, who had recently lost her mother, that they were in a legitimate relationship and would go on to marry.
She believed she would move to Canada and marry him when she turned 18. He also told her he wanted "100 kids".
During the two years he preyed on her using online messages, at least one letter and audio messages, he sent naked pictures of himself to her. He also encouraged her to reciprocate with explicit images of herself.
This week, Tremblay was jailed for four-and-a-half years by a Canadian court, and the case has been held up as an example of effective co-operation between law enforcement across international borders.
Tremblay was convicted as a result of "good old-fashioned detective work" by gardai, coupled with expert knowledge in a Canadian prosecutor's office with a well-resourced cyber-crimes unit, prosecutor Craig Krieger told the Herald.
Speaking about the case for the first time since Tremblay was sentenced, Mr Krieger outlined a detailed and comprehensive investigation that eventually left Tremblay with little option but to plead guilty.
Mr Krieger became involved in the investigation in March 2015, five months after locals in an Irish seaside town alerted gardai to inappropriate behaviour between Tremblay and his young victim during a 10-day stay at a holiday home.
"At that stage, the gardai had gotten quite far. I want to give them credit because, even though they probably figured out early on that they would never see the offender again in Ireland, they nevertheless did quite a bit of old-fashioned legwork to gather evidence," he said.
This evidence included a substantial paper trail, including accommodation records and car rental details for Tremblay's visits to Ireland. CCTV footage showing Tremblay with his victim as they shopped together was also collected.
There was also a significant amount of correspondence between the two on WhatsApp, including audio messages he had sent the victim.
Canada's criminal code allows the authorities there to prosecute offenders who commit sexual crimes against children in other jurisdictions.
The investigation painted an upsetting portrait of how Tremblay preyed on the young girl.
"They met on a chat service, similar to Chat Roulette, but moved very quickly to other apps including WhatsApp," Mr Krieger said.
"He was upfront about his age, which at the time was 30 years old, and the conversation started off very friendly, then it escalated quite quickly."
The random nature of the meeting was "not unusual", Mr Krieger added, but he was keen to stress that the case itself and its transatlantic nature is not typical.
There is no reason to suspect Tremblay deliberately sought an Irish victim. "It was just from the spinning of the wheel, bad luck," Mr Krieger said.
Authorities were not able to recover all of the communication from their two-year correspondence, but what was recovered showed Tremblay had used flattery to convince his victim of the normality of their relationship.
Her devastated father, in his victim impact statement, described the communication as "brainwashing".
"We were able to show the judge the detail of the kinds of things he was saying to her. It was quite explicit eventually," Mr Krieger said.
Tremblay sent naked pictures of himself, along with explicit audio messages, disturbing details of which were recalled during court proceedings.
Tremblay travelled to Ireland at considerable expense on each occasion, but so-called "sex tourism" is not unusual and paedophiles will often show disregard to barriers such as journey distance.
"Many of these predators are so committed to fulfilling their twisted fantasies they will go to extraordinary efforts," Mr Krieger said.
"It doesn't matter what kind of quiet, peaceful, rural areas one is in - as long as one has access to electricity and an internet signal, these predators are committed.
"One of the things that I emphasised to the judge was that he was willing to cross seven times zones and deal with jet lag for only a seven-night visit and a 10-night visit… most people would be reluctant to go on that trip for only seven nights.
"That's another reflection of how fixated this guy was on satisfying his own pleasures and disregarding the effect on the victim."
This was Tremblay's first conviction for crimes against children.
In 2013, he was convicted of assaulting his now ex-wife but was given a "conditional discharge" and probation.
"His first flight to Ireland was less than a week after he was in court for that assault," said Mr Krieger.
A psychologist's report found that Tremblay does not display a preference for teens or pre-teens, but would he have continued to offend or preyed on another victim?
"I'm reluctant to make that kind of prediction but… the only reason this 'relationship' ended was because he was caught, because of the vigilance of the neighbours. He was still fully engaged in this 'relationship' at that time," said Mr Krieger.