I am engaged in a (slow) project to read all the Edgar Award winning Best Novels, starting with the first in 1954. #4 was Charlotte Armstrong's A DRAM OF POISON. I had been seeing Charlotte Armstrong's name on bookshelves since I first got into the adult section of the library, but I don't believe I'd ever read one of her books. Now I think I'll read some more!
This was the first of the books that I have really enjoyed, even though it still didn't fit the classic detective story paradigm. The LC subject heading was Romantic Suspense, and my library had the book (enclosed in The Charlotte Armstrong Reader, with two other novels) in the general fiction section, although some of her books are in its mystery section.
Based on this sample, Charlotte Armstrong wrote extremely well, was able to create characters with depth of personality that readers can care about, and to create page-turning suspense. Someone commented to me as I was beginning to read the book that it started off slowly, and I would agree, though the quality of the writing kept me going through the set-up part. When the suspense gets going it really takes off, and yet Armstrong managed to include a fair bit of humor, romance, and trenchant philosophy from a bus-driver with it all. I was even surprised by the ending! You'll note that I haven't summarized the plot -- it's a hard one to summarize without giving too much away. Just read it. You won't be sorry.