There's no indication something incredible is just metres away - one of those moments you'll remember for the rest of your life.
The Congolese jungle is as thick as ever; the whispers of trackers and the "thock thock" of machetes hacking through undergrowth are the only sounds.
We've been trekking through the mud for hours, so long that we've almost forgotten what we are here for. It's just one foot in front of the other now, with a gentle "sluuuurp" as each shoe works itself free from the mire. It's far too late to call it quits - that would just mean hours more trekking with no reward.
But then, as one of the trackers edges us into a clearing, there they are: the beasts we've travelled so far to see. At least, I think they are. The silverback - the daddy gorilla - just looks like a clump of grey hair from afar, like something an enormous cat might cough up. It's a bit underwhelming. But then he turns.
There's no forgetting that moment when you first stare into those huge gorilla eyes. Are you imagining the connection or does it really happen? The seconds tick by as we stare at one another, curious gorilla and gaping tourist. There's something primaeval going on here, something from hundreds of thousands of years ago.
Then all hell breaks loose. The kids have arrived. They come bounding into the clearing, the smaller one beating his chest in a way that surely happens only in cartoons. The mother lumbers in after them, keeping a casual watch as the kids eye off the tourists, and our group goes photo-crazy. No one's breathing a word, lest it shatters the moment.
One-on-one with mountain gorillas in the wild - and this is wild. The guides have AK-47s as well as machetes. The nearest civilisation is a few hours' hike away and isn't what you would usually think of as civilisation. It's a border town in the Democratic Republic of Congo, not a thriving Western metropolis.
We're given an hour with the gorillas. An hour can seem like eternity when you're chained to a desk at work but when you are staring at a family of mountain gorillas at play in a Congolese jungle, it tends to go by a little faster. It seems just a few minutes before the trackers are softly tapping us on the shoulder, motioning us back into the jungle.
And that's it. Life-changing experience over.
It's hard to take in. We plod back through the jungle in a daze, the silence eventually giving way to excited babble. What just happened? It's not until a day or so later that I can look back on it and ponder how I got to those gorillas; the events that allowed me to have that amazing experience.
And it was all down to luck and not my own doing at all. Like most of the best things that happen while travelling, the gorilla experience fell into my lap.
Before I met a girl called Maya, gorillas had existed, for me, as entertainment only: Donkey Kong, Magilla Gorilla, the YoGo advertisments. I was aware of their existence, I just didn't know where in the world they resided, nor how few there were left. I'd never considered the possibility of going to see them in the wild.
One day, however, a friend in Brisbane tried to set me up with a girl called Maya and everything changed. "You're both travellers," my friend said, "it'll be perfect."
It wasn't. But Maya and I did make a travel connection. We shared an obsession. We traded stories. Maya told me about a three-month truck tour she was planning to do in Africa later that year, one that would take in a gorilla trek in the DRC. "So," she said jokingly, "are you in?"
And in little moments like that, the axis of your life shifts.
I laughed that night, said, "Yeah, sure," but a seed was sown. The more I thought about it, the more certain I was this gorilla thing could actually happen.
Six months later I was standing next to Maya in that jungle, having one of the highlights of my life.
Pure luck. Like the guy I met later on that African trip, in Namibia, who set me up with a job as a cook for a European tour company. It turned out to be the best summer I have ever had.
Or like landing in Korea during cherry blossom season before I even knew such a thing as a cherry blossom season existed. Or the week I spent rock-climbing in Utah after a chance meeting with a couple of guys who needed someone to share the fuel cost from Colorado.
There's something to be said for good planning but the best travel moments are usually the lucky ones. The trick is to embrace them.
Have you ever had an amazing, life-changing travel experience that occurred through luck, rather than planning? Post a comment below.
Read Ben Groundwater's column on Sundays in the Sun-Herald.