April 1917...Sergeant Robert Green has rejoined General Monash's 3rd Division AIF, at Armentieres in France, where he hopes to resume normal soldiering duties. However, events beyond the Armentieres sector conspire to see him once again loaned to MI6 for yet another secret mission. A senior MI6 agent has been abducted by a criminal element and held at an unknown location somewhere near the major British training establishment at Etaples...