The Gold Comfit Box: A Thriller/Espionage Classic By Valentine Williams!

Excerpt:

Then, as in my experience newspapers are usually two or three jumps ahead of official sources with the news, I followed Albert's example and rang the Petit Bleu. At the newspaper they were polite but not helpful. About a dozen dead and injured had been extracted from the wreck, but they had no names as yet. I called the railway station and the ministry of Railways with no better result.

There was nothing for it--it would have to be a car. As I grabbed my wet hat and raincoat and slip...