The Great Impersonation plot
"DARING AS TWO MEN and twice as dangerous BECAUSE HE WAS..."
During World War I, an unconscious man washes up on a boat off the coast of Africa. Baron von Ragenstein recognizes the man as his exact doppelganger Sir Edward Dominey he used to attend school with. Von Ragenstein decides to kill Dominey and assume his identity. He travels to England and once there, Muriel, Dominey's wife, is very pleased with the change her husband has apparently gone through. Sir Ronald of Defense is giving the man he thinks is Dominey an important position within his department. The story gets more and more complicated when Muriel's lover turns out to be a competitor of Dominey and on top of that, Baroness Stephanie, a spy in love with von Ragenstein, appears.