Dagon and Other Macabre Tales is a collection of short fiction involving and peripheral to the Cthulhu mythos. The stories follow scientists, psychologists, academics, and other members of literate society in turn-of-the-century New England as they investigate and combat the malignant entities dwelling deep under the ocean and in the vast waste of the Arctic. The stories dwell on themes of isolation, the insignificance of mankind, and the vastness of the unexplored world.
Boasting the largest collection of book summaries, BookRags is the best option for titles you can't find elsewhere. They offer all of the basics (quotes, chapter summary, characters, historical context, literary criticism) but also walk through a few major topics that recur throughout the book, which can be particularly useful for essay writing.