At the turn of the century, Inspector Sam Blackstone finds himself seconded at the New York Police Department and investigating the disappearance of a reclusive Wall Street tycoon whose body guards were found brutally murdered.

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...