This Month's Question: What Horror Novel Should Everyone Read?

The Question of the Month has a simple premise: each month I'll ask a handful of authors to answer the same question and then I'll publish their responses exactly as I receive them. In these posts you'll discover how these authors think, giving you insight into where their darkest tales come from. These responses are listed here in the order they were received.

This month's question is: If you had to recommend just one horror novel for everyone to read, what would it be and why?

Shirley...