Clubfoot. Clubfoot was created by “Douglas Valentine,” the pseudonym of Valentine Williams (Trevor Dene, Detective-Inspector Manderton, Mister Treadgold), and appeared in nine novels from 1918 to 1944, beginning with The Man With the Clubfoot. Desmond Okewood is the nominal hero of the series. Okewood is a World War One vet who was retired from the trenches after being wounded on the Somme–he received a “gunshot wound in head and cerebral concussion” as well as shell shock. Okewood is drawn into espionage because his brother Francis has disappeared and so he, Desmond, has to go into Europe and behind enemy lines to rescue Francis. From there it’s a long series of jousts with much the more interesting character of the series, Clubfoot, a.k.a. Dr. Adolph Grundt, who repeatedly survives what seems like a certain death to return and plague the Allies. Clubfoot is big, ugly, lame from birth, a stereotypical Prussian, quite ruthless, quite brave, and responsible for countless infamies and wrecked lives. During the war he is the head of the Kaiser’s spy service, but after the war Clubfoot becomes the leader of an international espionage ring.
The Clubfoot novels are fun, with a great villain in Clubfoot. Well worth searching out.