Nathan is the author of the bestselling technothriller series The Fifth Column, which includes The Chimera Vector, The Seraphim Sequence and The Phoenix Variant. In his spare time, he discovers hidden places around the world with urban explorers and studies Systema, a little-known martial art and closely guarded secret of Russian special forces. Nathan has trained under USMC, SEAL team and Spetsnaz instructors, the Chiricahua Apache scouts and Aboriginal Australians. He also drinks tea.