Could this be the perfect book cover? The title is The Sleeping Sphinx (1947) by golden age mystery writer John Dickson Carr. (The story is actually still in print.) Some web searching has led me to think it originally had a dust jacket. It's a shame because I've never seen an image that single-handedly sums up "intrigue" better than this. My copy was a recent Christmas gift from my wonderful wife... talk about great taste!