May 1915. While thousands of Britons fight in the trenches, a severely depleted police force remains behind to keep the Home Front safe. In London, the sinking of the Lusitania sparks an unprecedented wave of anti-German riots and arson attacks across the city. Among the victims is the immigrant tailor Jacob Stein, found dead in his burnt-out shop.

London 1915. The sinking of the Lusitania sparks an unprecedented wave of anti-German attacks. Among the victims are the immigrant tailor Jacob Stein. Initially Jacob's killing appears to be the tragic excess of wartime hysteria - but for Detective Inspector Marmion the possibility that the assault was long-premeditated becomes unavoidable