Jesús Ariel Aguirre 
The War of the Angels [EPUB ebook] 

A mysterious object has been stolen from the British Museum. A group of religious fanatics intends to use it to give life to an evil creature, using an old lost language, that of angels. Adams, a young priest, together with the old chaplain Martin, will seek the help of Professor Thomas Dee, who knows Enochian, a language created by his great-great-grandfather John Dee.
In search of a forbidden book, they will begin this adventure that will take them through Spain, France, Italy, Germany, Greece, the United Kingdom, the Czech Republic, Russia, Turkey, Mexico and Antarctica itself. Following in the footsteps of Lovecraft and his Myths, they will seek the answer in the Necronomicon and other Grimoires that will teach them to close the evil portal. They will come across characters like Nostradamus, Rasputin, Alice Crowley, Van Gogh and Merlin. They will also delve into the mysteries of Kabbalah and Alchemy. They will analyze the Crusades, the Holy Inquisition, the Cathars and the Essenes. Only the Angels will be able to help them with their difficult mission that will take them through great libraries and unveil the mystery of the great Cathedrals.