The film's French version title is Sur le front scientifique.During the First World War, campaigns were frozen into inaction, mired in a trench warfare stalemate that lasted years.

The close relationship of science and warfare is evident when Andrew McNaughton, the former head of the NRC, becomes the commanding officer of the First Canadian Infantry Division (part of VII Corps).

Canadian scientists and technicians use wind tunnels to design aircraft, decompression chambers to help pilots cope with battle at high altitudes, X-rays to test forgings, and create precise measuring instruments to ensure that cannon barrels are made to exacting standards.

New technology has been introduced to make weapons more effective including the use of radio direction finders and degaussing apparatus on ships to protect against magnetic mines and torpedoes.

Typical of the NFB's Second World War documentary short films in the Canada Carries On series, The Battle of Brains was made in cooperation with the Director of Public Information, Herbert Lash.