Iain Sinclair's 'Our Silenic Compact' is a psychogeographical exploration of London's geological substrata in search of the city's meteorites. Classic Sinclair, it touches and expands upon many of the themes of his most admired works. Brian Catling's 'Ahnighito' is a historical epic-in-miniature, a fictionalised account of the discovery and transportation of the enormous, 34-tonne anhnighito meteorite from Greenland to New York's Natural History Museum in 1894, where it still resides.