Secret warriors: the spies, scientists and code breakers of World War I

New century, new world

Part 1: Aviators. The pioneers ; The new science ; Observing the war

Part 2: Code breakers. Room 40 ; The Great Game

Part 3: Engineers and chemists. The gunners' war ; The yellow-green cloud ; Breaking the stalemate

Part 4: Doctors and surgeons. The body ; The mind

Part 5: Propagandists. The war of words ; The war in pictures ; Masters of information

Epilogue: The first boffins.