Greenmantle by John Buchan

It has been a hundred years since First World War began.  How the world has changed in that time, and yet people are still fighting wars.  They are also still reading books.  John Buchan wrote several books during the war.  The most famous is The Thirty-nine Steps (1915) which is set just before war broke out.  Greenmantle (1916) is the sequel, and is set in the months leading up to January 1916.

Richard Hannay, now a major in the British Army, is recovering from wounds received in the Battle of Loos.  Sir Walter Bullivant of the Foreign Office offers Hannay a secret mission.  Something is brewing in Europe that threatens to set the Islamic world on fire.  What that something is Bullivant is not sure, but he tells Hannay:

The East is waiting for a revelation. It has been promised one. Some star – man, prophecy, or trinket – is coming out of the West. The Germans know, and that is the card with which they are going to astonish the world.

The Germans know; the British only have a cryptic three-word clue from a now-deceased intelligence agent: "Kasredin, cancer, v.I."  It is up to Hannay to scour Europe to find out who or what the threat is, and to end it, if possible.  And so the adventure starts.

Buchan has expanded Hannay's stage.  Whereas in the first Hannay novel the action took place in Scotland and London, our hero now travels to Berlin via Lisbon and strikes out from there for Constantinople and beyond.  Hannay is pursued on land and on water, by boat, car and on horseback.  As always, Buchan provides terse but highly evocative descriptions of the natural world - one of his great strength as a writer; and, as usual, once the action gets going it keeps going, only punctuated with brief respites to let everyone to catch their breaths before starting up again.

If you can suspend your disbelief long enough to get past improbable coincidences (and there are quite a few in this book), then Greenmantle is a first-rate adventure story.  And it is interesting to see what people were reading and enjoying during the First World War.