"Woohoo! Look what I got!" yelled Pedro, suddenly emerging from bushes on the side of the road. Above his head he was triumphantly clutching two large green plants.
"Weed! I got weed, man!" he said, a grin covering his face.
"Ah, hate to rain on your parade" said Chris, once the cheering had died down, "but possession of as little as one seed here can earn you ten years hard labour in a gulag. Oh, and people don't usually survive more than five or six years in gulags here."
Pedro scrunched up his nose and scratched his head. Then he sighed and looked down at the plants before casting them aside.
Here was Kazakhstan.
Here, pot grows abundantly along the sides of roads. Roads that flow like rivers through vast yellow and brown plains, empty but for the occasional wild horse or power pole.
We were driving the Kazakh roads in a convoy between a 1954 English double decker bus and a fully kitted-out Spanish ambulance.
Driving the bus was a Russian named Dimitri. Four weeks of almost non stop driving from London had left Dimitri looking and acting like an amphetamine junkie.
From our position behind him in the convoy, we watched in disbelief as he drifted erratically in and out of traffic, and on and off the road, treating the 13,000kg vehicle like a go cart.
Behind us, lights flashing and sirens wailing, was the ambulance.
Under Spanish law, ambulances must retire after six years. Three Spaniards - Ulyses, Pedro and James - were driving a newly retired ambulance from Madrid to Mongolia and making a documentary along the way. When they arrived in Ulaan Bator they were going to give the ambulance to a Mongolian hospital.
It was the first time we had had the chance of travelling in a convoy, and we found it to be a roller-coaster of dizzy highs and terrifying lows.
There were many upsides. For example, we now had Russian speakers, detailed maps in the Cyrillic alphabet and a golf club to hit stolen driving range balls at spectacular scenery.
It was also a lot of fun. The first night on the convoy roller coaster we camped on a spectacular Kazakh steppe, playing frisbee as the sun set and dancing around a campfire as the moon rose.
The frustrating downside was that, like all amusement park roller coasters, we spent most of our time waiting for it to get started.
The ambulance was simply not designed for thousands of kilometres of pot-holed roads. Every day it had a new suspension problem or flat tyre, menacing new rattle or clunking noise.
Even when the ambulance was finally moving, the bus set an erratic pace, the driver stopping to buy apples or chat to locals just when we felt momentum was building.
Initially this was not a problem, as we were in no great rush. Our only deadline was to be in Ulaan Bator by September 1, so that I could catch my flight home for my sister's wedding.
In a reasonably sized country - like France for example - our progress would not have been a problem.
But there is nothing reasonable about the size of Kazakhstan. It's vast. Really, really vast. Vastly vast. At ninth-largest country in the world, it's vast enough to fit New Zealand ten times over within its borders.
Day after day, the summit of every new mountain in this country revealed another sweeping, empty steppe. In the end it took us six days of driving most of the day, and well after midnight just to cross the country.
Despite the frustration of our slow progress, the drive itself was a constant pleasure due to the incredible scenery - some of it reminiscent of New Zealand, only without the fences.
"Just like in Lord of the Rings" the Spaniards said regularly, much to our satisfaction.
Unfortunately for Kazakstan, we were not the only ones impressed by its scale and emptiness.
As recently as 1989, Russia was still testing nuclear weapons in the north east of the country, irradiating over half a million people in the process.
Semey bears the sad legacy of this experimentation - its hospitals are full of patients suffering from cancer, mental illness and birth defects.
Needless to say, we refrained from bathing in the strangely turquoise lakes in the area.
After five days of continuous driving we looked and smelled more like homeless cowboys than rally drivers. But there was something rewarding about the dust on our trousers, the stench downwind of us.
We just felt sorry for the Kazakh locals who had to tolerate even more pollution by foreigners.
Distance travelled - 11,460km
Time zones crossed - 7
Nights on the road - 33
Nights of accommodation paid for - 6
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