No smoke on the water. The River Derwent, Sandy Bay. August 2012.   Two books this week. First up, The Death of Grass  by John Christopher. This is a neat little post-apocalyptic novel that centres around the human response to a virus that kills off all forms of grass. While the swiftness with which society reverts to savagery strikes me as perhaps a little off, there is great power in the descriptions of man's culpability for the disaster. Indeed, this one is a very prescient book. Recommended.   Second up is The Dying Animal  by Philip Roth. For a book that is ultimately about sex, it wears out its welcome reasonably quickly. A couple of imaginative paragraphs aside - Roth can  write, after all - you can't help but think to yourself, 'get over it, you filthy old bugger!' Only for the keen.