I like receiving personalized mail, the old-fashioned way, meaning a paper envelope with a letter of some kind inside and dropping through the letterbox of my house. Rarely are these completely boring, and sometimes they can be rather surprising and nice. It is therefore with curiosity that I, married man of 37 and with a teenage daughter and tween son, have found one such on my doormat today.

The post mark, I note, says it is from Oxford, England. And it has a first class stamp. Important then, perhaps? Oxford rings a bell, a bit of a coincidence for something, but I can’t quite think what. I live in the north of England, and have no connections to Oxford and never even been there, but it’s famous enough obviously. Oh, that’s it – wait! – them! That’s what it reminds me of.

I go and sit down at the dining table. ‘Breakfast’ table, to be more exact in the circumstances. It’s almost midday, and I had a big lay-in because it’s my day off work and I was up late last night having my customary, fairly dismal activities on the computer. Nothing illegal, I hasten to add, my tastes are purely women of adult age or at least on the cusp of it, and even if just the wrong side of the cusp I most certainly would be responsible and caring enough not to do anything with them. Not that there’d ever be opportunity, with any age of them. I’m okay-looking, but I’m married which always means a brick wall barrier to get beyond any flirting, or else lying about it. I don’t think I’d want the hassle, not to mention the potential hurt to my wife, so I’ve all but written off any prospect of an affair and I content myself with playing on the computer. Now, I open this letter.

There is indeed a letter inside, nicely hand-written and long, but there’s also something else which I feel demands the first look. It’s a photograph, printed on proper gloss paper – a good size, 5 by 7 – that you typically get from Max Spielmann. I’m familiar with them, because of my mountaineering hobby and the many pics I take and like to get printed. Mine never look like this, though. Fuck, it’s four girls! Well, young women, more accurately. Definitely at least 18 or over. Well, I know they’re 18 or over, because it’s them! Them! It was a few weeks ago I’d met them, on one of my treks in Scotland. Out there in the grand wilderness. They did not look like they look like in this photo, though, because then they were wet, bedraggled and tired and attired in expedition gear. Here, they are smart and in dresses – beautiful dresses – with beautiful slim bodies inside them.

So what the hell is this all about? Some kind of trick? A joke? But nobody knows about that encounter apart from they themselves, and it was perfectly innocent, but I omitted to tell my wife about it because I’m a sensitive guy and I reckoned the mere mention of it might give away the look of ‘that which I secretly wish for’, and thus depress her more than she is already depressed. She’s at work today. Oh, there’s a little piece of card in there too, with a phone number on it.

Must read the letter, my God the letter. I have a strong aspect of self-control and deliberation to me, I think, in keeping with my hobby – you have to think and make decisions calmly to stay safe – so now I decide to go into the kitchen and make some toast and a cup of coffee to sit down at my leisure, and to read in the best possible alert frame of mind. I’m hoping it’s nothing bad. I don’t see how it can be, really. I’d been a gent and they’d seemed perfectly nice sensible girls.

Dear Joshua,

Do you remember 6 weeks ago, in the Cairngorms? I hope you don’t mind us taking this opportunity to write to you. We ask you do keep this confidential, though, which is for your sake as well as ours.

Firstly, thank you very much for the assistance you gave us. We would surely not have made it back safely if not for that, or else needed the embarrassment of mountain rescue. However, there is one other very important thing you may be able to help us with. We do not ask you to do it for nothing, but please first read carefully what it is.

Yeah, I remember 6 weeks ago in the Cairngorms well enough and have been running it through my mind a lot since...

The Highlands of Scotland, and one of its most famous mountain ranges. I had gone up there in July to do a weekend’s walking, aiming to complete no less than 6 ‘Munros’ (peaks over 3,000 feet/914 metres). On the Saturday I did the two I aimed for, easily enough, but Sunday was the big day. Four peaks strung along an undulating and dramatic high level walk: Braeriach, Angel’s Peak, Cairn Toul and Devil’s Point, the first three of which break 4,000 feet.

The forecast was for ‘some cloud and showers’, but it turned out much worse, as can often happen in the Cairngorms. I was confident enough to look after myself, even if navigation did get difficult. It did, and I found myself totally failing to find Devil’s Point and coming down in the wrong direction. Not a disaster, because it only involved a couple of extra miles to correct it. It was in descending these rough slopes – ‘Buidheanach of Cairntoul’ – that I saw them, at a distance.

Four figures with assorted coloured waterproofs and big rucksacks, plodding down slowly in the thick grey drizzle, and I decided to make sure our paths converged as I very much liked the idea of some human company by now. It was soon clear they were not walking efficiently, not at all the experts that their gear at first sight suggested. One in particular seemed to be getting a lot of assistance from the others, whilst sometimes the others got ahead and then looked back and waited, exchanging words. Hell, they were all girls.

Not a huge rarity seeing intrepid girls/young women doing this kind of thing, but as soon as I greeted them it was obvious these four were having a very hard time. They looked at me with anxiety and urgency, quite clearly not wanting a mere ‘hello, nice weather, goodbye’ comment from me. One spoke, a slightly masculine-looking one but pretty nevertheless, who was evidently the leader. The other three, one of which was of Asian colouring and eyes, were all obviously pretty too even in their ragged and damp state.

“Can ye tell uss where we are on this map?” the leader asked, in an Irish accent, holding out the laminated thing.

“Sure.” I had figured out my error by now, and explained it easily.

They had made the same mistake, only in their case it was compounded by having far less fitness and getting exhausted, plus the struggling girl – ‘Ellie’ I was told – was soaked right through because her waterproof was substandard. She was shivering, not far from hypothermic I reckoned, and moving very slowly and not saying a thing. Endearingly courageous in her way. Another told me of bad blisters, whilst another had cramp, and they bickered between themselves about calling mountain rescue ‘or their supervisor’.

I played the mediator, and said no need. I could guide them to where they needed to be, which was a little stone hut called ‘Corrour Bothy’. There they had planned to spend the night, as the first stop in a three-night expedition for their Duke of Edinburgh Gold Award. Morale lifted a touch, they just about united on the idea and so we began the trek into the correct glen (which was where I needed to be heading anyway). For a start, I’d worked out which burn we were near and had to steer them away from a death-peril gorge they would have headed into.

We got down safer slopes, and trekked – trudged behind me in their case – along the ‘Glen Geusachan’ and around into Glen Dee where the bothy was. In fairness, the ground was awful, tussocky and squelchy because there was no decent path. They were knackered, not the tomboy so much, but the other three. ‘Ellie’ in particular was almost out of it, and once inside the bothy they had to give her a lot of attention. I felt obliged – indeed wanted – to stay for a bit and make sure they regrouped okay. I felt quite the hero, but I was also beginning to feel something else: ‘frustration’, let’s say.

They were organized enough to have dry clothing wrapped away in their sacks, and proceeded to put some of it on. The leader – Shannon – joked about ‘no need te stand on formalities out here’, and simply did a quick strip down to her bra and put a new top on. They helped Ellie – a very thin girl with a nice intelligent face, I noticed now – into hers, and she did not object. The other two were less easy about it, I think, and a demure-looking brunette named Charlotte didn’t do anything about changing. The Asian, who was in fact American named Althea, was either dry enough already in her successful gear or else also too reticent. She had an easy smiling demeanour which gave away absolutely nothing.

I tactfully pretended I was seeing nothing, and I focused on getting the fire started for them and listening to their explanations of their mission with their intermittent repeats of ‘thanks so much’ or words to that effect. The other two were English, and they were all high-flying Oxford University students, as well as pursuing this ambition of the DofE Gold Award; I knew of it well enough, as a while back I’d decided to qualify as an expedition Assessor myself although never used it yet. I told them about this, and praised them for their determination and said I could well understand how they ‘hated to fail at anything’, as Shannon put it, with the others muttering concurrence, even the weary Ellie.