It's 1945, last two months of World War II. The American and Russian intelligence services are desperately looking for the secret 'Apparatus'- a device which helps Germans to decipher Soviet telegrams. Functioning of this machine is associated with one of the biggest secrets of World War II - construction of the atom bomb in the underground laboratories of Lower Silesia complex "Riese". The tracks lead to the Tschocha Castle in Lower Silesia. Polish agent- Johan Jorg arrives there and he is employed as a cryptologist to work with 'Apparatus'. Jorg passes information to the radiotelegraph operator - Natalia. Thanks to her, a special intelligence group, led by Howard Compaigne -American cryptologist and commodore, and by Andrzej Czerny -an officer of Polish intelligence, prepares for a strike. Russians also send their agents near Tschocha. The castle is ruled by Hans Jacob Globcke, the head of security who is supported by Matheas Beer.