Douglas Brunt’s The Mysterious Case of Rudolf Diesel: Genius, Power, and Deception on the Eve of World War I takes up the strange circumstances surrounding the disappearance of the inventor of the eponymous engine, who apparently vanished while traveling across the English Channel on the steamship Dresden in September 1913. But the identity of a body recovered nearby was disputed, and there was never any real proof that Diesel had even been aboard.

Further muddying the waters? It’s unclear whether his wife was with him, and his final destination — the United States, presumably — remains an open question. He was also the only passenger alleged to have gone missing. Diesel had business agreements in the U.S., notably with Anheuser-Busch in St. Louis, and perhaps he ended up there.

The arrangements of his business affairs, especially the instances where he licensed his revolutionary engine, were complex but perhaps typical for the era. He had dealings in Germany — which was no surprise since he was educated there and developed his engine there — but he also had interests in Paris (where he’d spent the first part of his life).

It was natural for me to take an interest in this book: I grew up in St. Louis and spent two decades in Germany and France. Also, the inventor of the diesel engine was hardly a nobody, even though Brunt makes the case that he was not given his due. Somehow, Diesel never really got credit for developing the engine that literally bears his name, and his disappearance on the eve of World War I all but ensured his loss to history.

The book — which chronicles, among other things, the friction between Diesel and two powerful figures: Germany’s Kaiser Wilhelm II and John D. Rockefeller, the world’s richest man at the time — lives up to its blurbs that it’s equal parts Walter Isaacson and Sherlock Holmes. And it’s well-written, first appearing in 2023 (I discovered it in the remainder section of Politics and Prose Bookstore in Washington, DC).

It’s not really a biography, although it reads like one in places. And whether or not you accept Brunt’s thesis about Diesel’s disappearance — you’ll have to pick up the book for yourself to learn the specifics — it’s a compelling one that fits the facts. Even so, the man’s vanishing remains an unsolved mystery.

Darrell Delamaide is a journalist and author in Washington, DC. He is the author of four books, two nonfiction and two fiction.