"Subterrâneos da Morte" (The Guardians: Dark Ways to Death) / Hardcover – 1968 by Peter Saxon (house-name of W. Howard Baker e Wilfred McNeilly): "A Guardians Novel, pledged to wage war against Satanism!!"
Dark Ways to Death (The Guardians #2) by Peter Saxon -- Black magic, satanism, necromancy, witchcraft, sorcery, voodoo, vampirism...wherever and whatever the agents of occult Evil are, THE GUARDIANS are there to combat them with their own more-than-mortal powers. In this second thrilling exploit, The Guardians meet their most fateful and perilous challenge in a nightmare maze beneath the city streets - where the Dark God meets his worshippers and lures The Guardians to a doom beyond death!
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http://www.bibliowiki.com.pt/index.php/The_Guardians_(série)