The smell was wafting through the bus like burnt toast, only slightly more ... acidic. It didn't smell like any of the usual tour bus odours: socks, Pringles, day-old Coca-Cola.
"Hey, Ben, I think there might be a problem down here."
I glanced at Sarah, the tour guide, perched on her throne next to the driver, and we both rolled our eyes. There was always some sort of problem back there.
The question was, whose turn was it to deal with it?
"Go on," Sarah said, tilting her head towards the commotion in the back of the bus.
A few seconds later I did as I was told, pushing past the passengers sprawled across each other, making my way to the middle of the coach where someone was pointing to the toilet. "There's a pretty weird smell coming from in there."
Well, that'd be a first. This was a trans-European coach tour with a bunch of lawless school-leavers, all of whom were having to put up with my dubious culinary skills on a daily basis - bad smells came with the territory for all of us.
Still, this didn't smell like anything I'd sniffed in a tour bus before - it was much smokier than usual - so it was worth investigating.
I pulled the toilet door open. Nothing. It didn't even smell that bad. Weird.
Back in the aisle, however, things were worsening. That's when I saw the trickle of smoke edging its fingers around the door of the cabin built under the coach for a second driver to sleep in. This was trouble.
I wrenched the door open and stared in amazement. Flames. Large flames, engulfing the mattress, licking the ceiling under the passenger seats.
"Hey Baa-Baa!" I yelled at our Kiwi driver.
"We're on fire!"
What happened next is a blur of well-meaning incompetence. As Baa-Baa pulled the coach to a halt on the side of an Austrian country road, I decided it was hero time and grabbed the first available fire retardant: a bottle of mineral water.
So there I stood, ineffectually trying to put out a raging fire with a small bottle of drinking water, until Baa-Baa elbowed me out of the way and gave the thing a few squirts from the fire extinguisher kept next to the toilet. (As in, right behind me.) Tsssh, tsssh. Fire out. Phew.
The whole place stank, of course, so we piled the passengers out onto the side of that same Austrian country road and waited for help to arrive. This, too, was a problem.
Paying passengers, in my experience, don't appreciate life-threatening infernos on their tour buses. They also don't appreciate having carefully laid plans thrown awry. We had places to be tonight - any delay would mean an experience missed. Money wasted. Disappointment.
I scanned the faces lined up at the side of the road, bracing for complaints. Even the lowly cook has to deal with the whingers. Instead, however, I saw the weirdest things: smiles. The mad buggers were actually enjoying themselves. One of them waved me over.
"Mate, how funny's this! Betcha Baa-Baa left something flammable in there." Another nodded. "Reckon we'll get to Switzerland tonight? We might get another night in Austria!"
This group of passengers would go down in history as the Best Passengers of All Time.
This wasn't the first setback they'd encountered on their all-expenses-paid holiday of a lifetime. We'd pumped them up for days about Orvieto in Italy, only to arrive and find that the funicular staff were on strike. We had to stay in Venice an extra day waiting for a new driver, after our original coach captain fell down stairs and broke his leg.
Normally this would be cause for mutiny on the motorways, the sort of long faces you'd expect to see from people dragging themselves in to work on a Monday morning. "But our itinerary said we were going to Orvieto," and so on.
But not these troupers. They just shrugged it off, laughing at the unpredictability of travel. Things go wrong - might as well make the best of it.
Consequently, the Best Passengers of All Time had one of the Best Tours of All Time. We bumbled around Europe in our accident-prone way having the trip of a lifetime.
There aren't many valuable life lessons you can learn from drunk 18-year-olds but this was one of them: things are inevitably going to go wrong when you travel but what will make or break your trip is how you react.
You'll miss trains, you'll break down, you'll get ripped off and you'll wind up in places you'd really rather not be. You can either get worked up about these events or you can smile and take them in your stride.
C'est la vie.
We didn't make it to Switzerland that day but everything worked out for the best.
Baa-Baa was absolved of blame for the fire, I learnt where the fire extinguisher was kept and we got another night in Austria.
Have you ever faced something going seriously wrong on a holiday? How did you deal with it?
Read Ben Groundwater's column on Sundays in the Sun-Herald.
Hope you're enjoying the Backpacker blog – there will be a new one published every Tuesday and Wednesday on the Fairfax Media websites. To contact me with any topic suggestions or personal abuse, visit my website, follow me on Twitter, or email me at firstname.lastname@example.org.