In 1812 two mighty armies manoeuvred across the Spanish plains. They were finely balanced, under skilful leaders. Each struggled to gain an advantage. Wellington knew that if he defeated the French, he could turn the tide of the war.
Good intelligence was paramount, but the French were using a code of unrivalled complexity - the "Great Paris Cipher". It was a daunting challenge, and Wellington looked to one man to break the code: Major George Scovell.