Greenmantle recap

During the First World War, Richard Hannay is sent to discover a German plan to provoke a vast religious uprising through the Ottoman Empire. With Sandy Arbuthnot, Peter Pienaar, and American agent John Blenkiron, he travels undercover across wartime Europe toward Constantinople, following the cryptic name Greenmantle. Posing as an anti-British Boer, Hannay survives German suspicion and the pursuit of Colonel von Stumm. In Constantinople the agents learn that the brilliant Hilda von Einem intends to harness devotion surrounding a dying holy man and direct it against the Allies. Their separate disguises and investigations converge as the action moves east toward Erzurum. Sandy turns the symbolism of Greenmantle against the plotters, while Hannay and his friends escape toward the advancing Russians. Hilda is killed amid the final battle, Erzurum falls, and the planned rising loses the leader and moment it required. The four agents survive, having prevented Germany from converting religious prophecy into a strategic weapon.

In late 1915 Richard Hannay, now an army officer, is summoned by intelligence chief Sir Walter Bullivant. Britain has learned that Germany may be preparing to exploit a powerful current of religious expectation within the Ottoman world, threatening Allied positions from North Africa to India. The evidence is fragmentary, reduced to mysterious words and names rather than a clear plan. Hannay accepts the task of tracing the scheme from Europe toward Constantinople. He recruits three men suited to unconventional work: Sandy Arbuthnot, a linguist and expert in eastern cultures; Peter Pienaar, Hannay's trusted South African scout; and John S. Blenkiron, an American agent whose poor health makes him seem harmless. They agree to travel by different routes and identities, with little certainty that any of them will reach the rendezvous.

Hannay and Peter enter Germany disguised as Boers hostile to Britain, Hannay using the name Cornelis Brand. The cover lets them present their knowledge of South Africa as evidence of sympathy with Germany, but every official encounter risks exposing them. Hannay's impatience and Peter's distinctive abilities must be hidden beneath their roles. They are drawn into the orbit of Colonel von Stumm, a violent and suspicious officer who sees the supposed Boer as potentially useful but does not trust him. Hannay gathers signs that the eastern undertaking is real and closely guarded. His path is increasingly controlled by the Germans, turning the mission from covert travel into a struggle to preserve his identity long enough to move toward the Balkans.

An encounter with Herr Gaudian, who knew Hannay in Africa, threatens to destroy the Boer disguise. Colonel von Stumm's suspicions and violence keep Hannay under immediate danger, forcing him and Peter to escape the tightening German net. They continue southeast through winter conditions and cross toward Ottoman territory under severe physical strain. The agents remain separated, and Hannay has no proof that Sandy or Blenkiron has survived his own route. What he has learned, however, confirms that the eastern scheme is real, closely guarded, and larger than a conventional military operation. Reaching Constantinople without exposing the mission becomes his immediate goal.

Hannay reaches Constantinople, where Ottoman officials, German advisers, and secret agents make open inquiry impossible. Blenkiron reappears with information gathered under his own cover, and Sandy has penetrated the religious and political world surrounding the conspiracy far more deeply than Hannay could have done. Hilda von Einem is again at the center of events, working with leaders who hope to unite spiritual expectation with the Central Powers' campaign. The clues begin to point toward Greenmantle, not simply as a password but as the title or identity of a sacred figure. The mission shifts eastward toward the war zone, where the conspiracy's political promise and the Ottoman army's operations are about to meet.

The agents learn that Greenmantle is an ailing holy man whose death may release immense devotion among his followers. Hilda intends to capture that moment and attach it to the German-Turkish cause. Sandy's knowledge and adopted identity allow him to move within the same symbolic world, making him essential to preventing her from controlling the succession. Hannay, Peter, and Blenkiron face pursuit as they travel through eastern Anatolia toward Erzurum, where Russian forces are advancing. The contest is now both strategic and personal: if Hilda can bring the expected religious leader into the campaign, a local battle may become the beginning of a much wider revolt. The British agents must survive long enough to reach friendly forces while helping Sandy break the link between prophecy and the Central Powers.

Near Erzurum, the separate strands of the mission converge amid the Russian offensive. Sandy turns the expectations associated with Greenmantle away from the use Hilda von Einem planned, depriving the conspiracy of the spiritual leader it needed. Hannay, Peter, and Blenkiron struggle through the collapsing Ottoman position toward the Russians while Hilda pursues them into the battle. She is killed during the final fighting, and with her death the organizing intelligence behind the scheme disappears. The Russians capture Erzurum, transforming the military situation before the planned rising can be launched. Hannay and his three companions survive and reunite, having followed Bullivant's fragmentary clues across Europe and prevented Germany from converting the authority of Greenmantle into a weapon against the Allies.

Hannay, Sandy, Peter, and Blenkiron escape the conspiracy's immediate reach and make for the Russian lines while the Ottoman army prepares for battle near Erzurum. Sandy uses the authority and expectations surrounding Greenmantle to disrupt the spiritual force Hilda von Einem intended to place behind the German-Turkish campaign. Hilda follows the fugitives into the fighting and is killed as the military position collapses. The Russian assault succeeds, Erzurum falls, and the feared uprising is never launched under German control. Hannay survives the retreat and battle with his companions, their scattered routes finally converging in success. The original clues have been explained: Greenmantle was the dying holy figure at the center of the plan, while the conspirators' attempt to command his influence depended on Hilda. With that scheme broken and the eastern front shifted by the Russian victory, Hannay's mission ends and he returns to Allied service.