I've known that E. Phillips Oppenheim was a very popular author during the early years of the 20th century. We had, or used to have, one of his books lying around the house for as long as I can remember. But, I've never read him before. Until now, that is. Although this book didn't capture my fancy all that much, I think it was more the subject matter than the writing and plotting. So, I'll likely try Oppenheim again.
This book has some intriguing ideas, but in the end, I don't think they really make sense. People end up doing things that are so improbable, given their previous histories, that what happens in the book could never happen in real life. I like plot twists, but they must make some vague kind of sense.
So anyway shortly before the beginning of World War I, we have a dissolute English baron, on the verge of starvation and death, wander into the camp of a German baron. They're in East Africa. It turns out the two know each other. They'd gone through public school and Oxford together. They also resemble each other rather amazingly. If you didn't know better, you'd mistake one for the other, at least by looks. Their personalities are sufficiently different, one could tell the one from the other in a twinkling of an eye (to borrow an inapt Biblical expression).
Well, the German baron gets an idea. Why not kill off the English guy and impersonate him back in England? He'll become a sort of under-cover spy for the Kaiser. He knows the Kaiser is up to no good and is arming so as to extend the German empire across much of Europe, with subsequent inroads into the rich trading areas of Asia. So, it would be most helpful for the fatherland to have an embedded presence among the British ruling class. So, he sends the English baron back into the bush with only whiskey in his water bottles. That should kill him off. And if not, the German baron will follow along in a few days to make sure the Englishman will no longer be able to mess up his plot.
So, then we're off in England where this German baron purports to be the English baron. People are much surprised that he's reformed his dissolute ways, but mostly, he's accepted with open arms, in part because he's paying off all his massive debts. His two main problems are the Hungarian princess who used to be his lover (and the cause of his exile to Africa because he'd killed the princess' husband), and the insane wife of the English baron (who was the cause of the English baron's exile in Africa to escape being killed by his insane wife). The returned English Baron/German spy must act honorably toward both, which means keeping his hands of someone else's wife, especially given that she's insane, and also means keeping his hands off his former lover so as not to blow his cover. Something like that.
Anyway, I won't go on. There are some surprise plot twists that I wouldn't want to spoil. As I said above, it's an intriguing and well written tale, but falls a bit flat at the end because of it's improbability.