the story is told by Rouletabille's friend, some kind of lawyer who's never really established as a character other than that he can't really figure out what Rouletabille is up to. Rouletabille is a very young journalist who has a knack for solving unsolvable crimes. the entire mystery hinges on the victim/accused refusing to explain what they know.

I think I've read enough locked mystery rooms (although not my favorite mystery sub-genre) that I can now start to imagine some of the other explanations for these seemingly impossible crimes. I had figured out pieces of the solution and found the drama of the whole situation a bit over the top.