Book #1 in the Bernard Newman series.
A supposedly fictionalized account of his own early days as a spy, this book depicts the adventures of Bernard Newman as a British spy against WWI Germany. This will include investigating the attempted assassination of the sitting Prime Minister of England in 1918, Lloyd George. Marshall is a Sergeant with "the Special Service men from Scotland Yard" who shows up towards the end at Newman's request for help with the Lloyd George matter.