Hake Talbot's 1944 masterpiece, Rim of the Pit, is one of the best "impossible crime" mysteries ever written (at least in my humble opinion). It's the subject of the current book discussion under way among the members of the "4 Mystery Addicts" group at Yahoo. I'm the question master; between now and October 30, I'll be posting a total of six questions for the group to consider and discuss. The first question is already posted; the second will be going up there tomorrow. If you've read the book, I invite you to come discuss it in conversation with the group - I'd love to know what you think.
If you're not a member of the group yet, by the way, I strongly encourage you to join (you can do it at the link above) - it's free, of course, and you'll find discussions there about every possible sub-genre of the mystery field and the very latest books by your favorite authors.
For those who may have missed what I had to say about Rim of the Pit in the past, here's a link to an earlier post.