Marian Rejewski, son of Josef and Matylda, is born in Bydgoszcz, Poland. The city is part of an area annexed by the German Empire. In 1913 the majority of the Polish population have left the city and Marian is being educated in a German speaking school. As part of the peace talks following the First World War, Bydgoszcz is returned to Polish control in 1919. Marian excels in maths and continues his education at Poznan University. Poland, sandwiched between Germany and Russia cannot afford to be ignorant of any plans of expansion their neighbours might harbour.

The Polish Cypher Bureau discover that the Germans are using a new type of code which they are unable to decipher. The Bureau decide to recruit maths students in a new approach to code breaking. Marian is recommended to the Bureau and along with 25 other students, attends the secret course in code breaking. Having been supplied a commercial enigma machine and a set of user manuals, Marian sets out to break the Enigma code. Their work is carried out with utmost secrecy to ensure that the Germans do not realise that their code has been breached. The Polish Cypher Bureau are desperate to decode the messages as quickly as they can as there is an increasing risk of war with Germany...

Author Eilidh McGinness lives in France and started writing a few years ago. Eilidh is a fully qualified lawyer. She studied law at Aberdeen University and completed her training in Aberdeen-shire. Eilidh was born in Dingwall, Scotland. She is a member of the Bordeaux Writers Group, An Aquitaine Historical Society and The Franco-British Chamber of Commerce.