The Burrowers Beneath by Brian Lumley

"The Burrowers Beneath" is the first of the Titus Crow series by Brian Lumley. The story centers around Titus Crow and his friend Henri-Laurent de Marigny who discover, through a few other people, that Shudde M'ell (one of the Great Old Ones) and some of his fellow Cthonians have escaped from the prisons of the elder signs.
Since escaping, they have primarily remained beneath Africa. However, at various times their eggs have been discovered and removed. This has caused the Cthonians to move and pursue their young.
The story was a lot of fun and I would definitely recommend reading it if you enjoy the Cthulhu Mythos. Unlike many other stories within the mythos, Crow and his cohorts fight back. They even manage to kill a few lesser Cthonians. They are not immune to the mental effects exerted by the creatures but they defend themselves with elder signs, protection elixirs, etc.
One of the things I really enjoyed about this story was the number of books Lumley references. Some of these books are fictional and some of them are actual, published works. I kept a list as I was reading but after a while I got tired of doing it. In the end I believe I missed 2 or 3 books. Here is the list I created in the order that they were mentioned:

• The Necronomicon by Abdul Alhazred (Created by H.P. Lovecraft as a counterpart to the Cthulhu Mythos)
• Cthaat Aquadingen (Fictional)
• Pnakotic Manuscripts (Fictional)
• R'lyeh Text (Fictional)
• Unaussprechlichen Kulten by Freidrich Wilhelm von Junzt ("Nameless Cults" - Fictional)
• De Vermis Mysteriis by Ludwig Prinn ("Mysteries of the Worm" - Fictional)
• Cultes des Goules by Comte d'Erlette (Fictional)
• Notes on the Necronomicon by Feery (Fictional)
• Revelations of Glaaki (Fictional)
• The Golden Bough by James G. Frazer (Real - This is a study of magic and religion. I own a copy)
• Witch Cult by Margaret Murray (Real - Actually titled "The Witch Cult in Western Europe")
• Liber Miraculorem by St. Faith of Conques (Real - Actually titled "Liber Miraculorum Sancte Fidis)
• History of Magic by Eliphas Levi (Real - I own a few other works by Levi but not this one)
• Unknown "Slim Volume" by Commodus (Fictional - While the actual name of the book is not given by Lumley, he claims that this book was written around A.D. 183. Commodus was Emperor from A.D. 180 to 192 when he was assassinated.)
• A Temple to the British Druids by William Stukely (Real - Actually titled "A Temple Restor'd to the British Druids)

I actually really enjoy when authors reference other works. When the works are fictional, it allows me to imagine what they look like and what they contain. I can imagine the author scribbling away in the middle of the night at a book that will only be read and understood by a few. When the works are real, it gives me new books to read. Either way it's a win.