A couple of passers-by stumble upon the drowsy and upset woman in Hunter Square and ask if she is OK.
She isn't. Amongst her sobs, the young girl manages to slur that she has taken a heroin overdose. She tells them she just can't face living any more.
Within minutes, two night wardens are on the scene tending to the increasingly ill woman. They comfort her, make sure she doesn't fall unconscious and get her to hospital.
That was 16 months ago. The girl made a full recovery – and said she was glad she was found alive that night.
Such incidents are all in a day's – or rather night's – work for Edinburgh City Council community safety officers Richard Brown, 45, and Ricky Barclay, 31.
There's a broad range to the work of the duo – and the 55 other community safety officers across the city, who first started walking the streets in November 2008. At the more serious end of the scale, Richard and Ricky are on the lookout for people at risk of taking their own life.
But they also scan the streets for people who are saturated with alcohol, fly tippers, underage drinkers, dog fouling, street litter control and those dumping materials – such as street cones or pint glasses – that might pose a hazard to others. They watch intently for those lurking in dark corners, lonely individuals dawdling on the side of a bridge or people curled up on park benches. At weekends, in particular, a combination of alcohol or other substances, late nights and socialising can be flashpoints for the upset and vulnerable.
Ricky explains: "The case with the girl who took a heroin overdose was particularly horrific, but there is so much going on across the city. Sometimes you can't even walk ten feet without stumbling across something. It's probably most common to find drunk people. It is incredible how many girls we find in tiny miniskirts and boob tubes who have fallen asleep in an alleyway or on a park bench in the middle of winter.
"People also throw traffic cones off bridges or chuck around tables and chairs. On North Bridge in particular we had a problem with intoxicated people who were urinating from the top of the bridge on to people below. Nobody can fail to notice the homeless people on our streets. We make sure they are OK and aren't aggressive."
This week, in particular, the safety duo are on the lookout for people who seem predisposed to injuring themselves. As part of Suicide Prevention Awareness Week – which has been marked with powerful posters demonstrating vulnerable people vomiting up the word "suicide" – the team are visiting all of the "suicide hotspots" across the city and are trying to spread the word that there are other options.
In particular, the team scan bridges, the Meadows, Calton Hill and Canongate Kirk for those in distress.
But tonight the Capital appears quiet. A few scantily-clad girls click along the streets to the various bars, and small crowds jostle with friends, but mostly the streets are bare. "The volcanic ash has a lot to do with that, believe it or not," Richard says. "The load of stag and hen parties we'd usually get aren't making it across to Edinburgh."
But even something like a natural disaster can't curb somebody who is intent on taking their own life. On cue we stop at one of the four bridges the pair normally check on their nightshift, North Bridge.
Apart from a few empty chip wrappers, the area is still. But a couple of eye-catching Samaritans posters on the walls indicate that not all the people who visit here come to appreciate the view. Richard says: "It's a relatively new initiative, the posters. North Bridge is known as a bit of a suicide attraction – the people who often come here have resolved to take that action – so the posters give them one last chance to think again and reassess their choice.
"You find that sometimes, psychologically, this is the trigger they need to get help, to inspire second thoughts."
Scanning the bridge carefully, Ricky adds: "We look for the key signs – if somebody is disorientated, confused, walking around the bridge area and staring intently over the edge. If we see somebody who is upset, we try to comfort them and get them to a safer spot. We don't usually touch them because that can make some more upset."
The pair, who work from 5pm to 4am, four nights per week, work closely with the British Transport Police, taxi wardens and the police.
The next stop is Canongate Kirk. As eerie as it seems as they move their flashlights across the grave stones, Richard explains that often all they find lurking are under-age teenagers enjoying cider or a homeless person seeking shelter.
"But it's a dangerous place to hang out," Richard says, pointing to one crypt in particular. "Just recently we did a routine check through here to find a young lad. He'd been jumping around and the roof of the crypt had fallen on his leg, shattering it. It's lucky we came by."
Tonight there is no sign of bored teenagers looking for an adventure, but the team stumble across a makeshift home. It is filled with dirty clothes, a sleeping bag – and a pile of used syringes in the corner.
Ricky says: "We'll often find dens made by homeless people, but they're hard to pin down because they tend to beg across the city. We'll visit the spot later to see if we can find the person in need of help."
As the clock creeps to 1:30am, Ricky and Richard note that it is prime time for the first wave of drunken – and therefore potentially upset or aggressive – revellers to filter out of the pubs. They jump back in their van – equipped with high-quality CCTV – and cruise by the Omni Centre and the Meadows.
True to the pattern of the night, all is well. Taxi wardens bundle jolly pub-goers into taxis, while others stumble home with their food of choice.
But as the pair wind up for a quick break, they experience their first aggressive member of the public of the day. The young man grabs the side of the van and tries to clamber in after mistaking it for a taxi. When he is told the truth, he casts a stony look at Ricky and Richard before spitfiring out swear words and challenging them to a fight.
"We'll do nothing right now, but we'll radio to keep an eye on him," Ricky says as he watches him slump around a corner. A few seconds later a steaming stream of urine starts trickling down the street. Shaking his head, Ricky says: "Probably not the best place to pick a fight, outside the police station."
HARD-HITTING AWARENESS CAMPAIGN
A POWERFUL TV advert designed to tackle the issue of suicide is currently being aired in Scotland to highlight what help is available for those feeling like they have no way out.
The hard-hitting clip features a young man going about his everyday life. But when a friend notices he's looking a bit withdrawn and asks if he is OK, the young man starts to choke and his friend moves swiftly to perform the Heimlich manoeuvre on him. He subsequently vomits the word "Suicidal".
The aim is to show the best way of tackling suicidal feelings is to talk about them and to show the relief that can come with that. The advert is part of an ongoing campaign by Choose Life, Scotland's national strategy to prevent suicide.
Statistics show three out of four suicides in Scotland are men, and younger men are at even greater risk.
For more information visit www.suicide-prevention.org.uk