This is a classic book in apocalyptic fiction genre that you'll find in a lot of lists set up by fans on various web sites. It was written at the very beginning of the 20th century but the version I have was published in 1930 after some rewriting. Although most people rave over this book, although it was original at the time, it's nothing special now in my opinion as a lot of similar books have been written since.
The story features a man who goes on a voyage to the North Pole in order to fulfill a challenge and become rich in the process. Partly driven by his fiancee, he basically cheats and murders his way to be first to the pole and win the cash. Of course, in those days expeditions of this type took a long time and by the time he heads for home it's many months after he left England. Everyone he finds along the way is dead, presumably killed by a mysterious purple cloud that seems to have covered the entire globe except, luckily, the North Pole.
The rest of the book follows the man as he travels round the world slowly going crazy. That's essentially it, but it is more interesting than it sounds. The two things that spoiled the book for me were the rather dated language used (which isn't that hard to follow, to be honest), and the horrible personality of the main character, Adam (which for me is a big problem). I didn't get the feeling that he deserved to survive, but maybe that's the point.
If you like end-of-the-world stories then by all means try this book, but I have read a lot more than I found more enjoyable.