The Shadow Over Innsmouth

A highly recommended read. One of the better Lovecraftian books.

The plot is pretty straightforward - young man visits a town with a queer reputation and gets the shock of his life.

The atmosphere is great - in a chilling, mysterious and dark kind of way. You can almost feel the dread as you follow the protagonist's trek through Innsmouth. The twist at the end of the book is a really fine touch.

Highly recommended for anyone who hasn't read a book on Cthulhu.