The key elements of the book which could be implemented in visual form are: Russian cold-war era Pioneer nuclear missile(s), cold Siberian mountain ranges, maps or indicators of global travel, nuclear explosions, men in the shadows, guns, etcetera. I've considered the idea of silhouettes of the protagonist and co-protagonist in the forefront of a nuclear blast. But hey! You guys are the experts. Something abstract could be interesting also. The feel of the book is modern, with a lot of references to cold-war era Russian culture. Font styles that play would that would be fine. A modern, intense, thrilling feel would be great also. It's an action thriller.