England, 1940, during World War II. An MI5 officer, codenamed Jack King, infiltrates a network of conspirators, a British fifth column sympathetic to Nazi Germany, in order to control the organization and destroy it in the event of a German invasion. But who was he? A single person or several?

• 13 Productions
• Planète+
• Frédéric Sanchez
• Sébastien-Yves Laurent
• Stephen Dorril
• Thomas Hennessey
• Michael Jago
• Michael Smith
• Nigel West
• Charlotte Brady