In the midst of World War II, the battle under the sea rages and the Nazis have the upper hand as the Allies are unable to crack their war codes. However, after a wrecked U-boat sends out an SOS signal, the Allies realise this is their chance to seize the 'enigma coding machine'.

A thought provoking documentary feature film providing a comprehensive exploration of the evolution of signals intelligence over the past century. Whether you're intrigued by the secretive world of intelligence agencies or concerned about the implications of digital surveillance, this film will leave you with a deeper understanding of the role signals intelligence plays in society.

During the worst days of World War II, the British government asks the mathematician Alan Turing to unravel the mysteries of the German Enigma encryption machine, an impossible task to accomplish without the invaluable information that Hans-Thilo Schmidt, a disenchanted but greedy German citizen, had been handing over to the French secret services since 1931.