December 1916. Inspector Sam Blackstone is suspicious when he is called to the office of Superintendent Brigham, the new head of special branch and confused that Brigham seems to want to see him as little as Sam himself wishes to be there. An already stranger situation grows more strange when Sam discovers what he's there for: a German traitor wants 25,000 in exchange for secret intelligence on U boat locations and Max has specifically asked for Blackstone...