'Three weeks ago I was sitting in the back of a Russian-built tank as it sliced its way through the tundra of Siberia's northern Yamal Peninsula. I was part of an expedition north of Salekhard, the only city in the world to straddle the Arctic Circle's 66th parallel, to a camp where the nomadic reindeer herders known as Nenet had set up their chums, or tents. We had already been driving for many long hours, and now we were faced by a rising river that had to somehow be crossed if we were to make our way back to Salekhard and then across Russia's vast interior to Moscow, by train, and then, finally, home.' (Introduction)