Within the Devil's Grotto in Haiti, Jack Russell (as the Werewolf), Topaz and Brother Voodoo have come to find the reasons behind a plague of zuvembie attacks, as well as to search for their ally Raymond Coker. They have found Coker, captive to Dr. Glitternight, who has just ordered his false zuvembies to attack the heroes. Glitternight, using his tendrils of mystic light, binds Coker in midair, siphoning off his lifeforce, until Brother Voodoo sends the spirit of his dead brother Daniel into the sorcerer's body. The initial shock forces Glitternight to drop Coker (who is in the werewolf form he had been cured of), but Glitternight regains control and returns Daniel's spirit, riddled with evil energies, back to his brother, who collapses in agony. As Jack and Topaz battle the zuvembies, Brother Voodoo exorcises the negative forces within himself, and recovers in time shield the heroes behind a wall of mystic flame. However, Glitternight recaptures Coker along with Topaz and carries them away.
The battle ends just as Jack reverts to his human form, and he and Brother Voodoo follow the trail of their captive allies. They reach the pit they had passed earlier, where demons wallow in a foul red murk. Believeing what they seek is below, Brother Voodoo leads Jack in a descent down the side of the pit. When they pass below the surface of the red substance, they find themselves in another dimension, one filled with moonlets and planetoids. The moons transform Jack into the Werewolf again, but he retains his mind and speech. The pair fall toward a small moon and sink below its surface where they are met by the supernatural trinity known as the Three Who Are All. They tell Jack and Brother Voodoo their story: in this, their native cosmos, they were originally the Five Who Are All, including Glitternight and one other. Glitternight caused the disappearance of the fourth and turned against his compatriots. The Three defeated him and exiled his from their cosmos, ending up on Earth which he intends to reshape in his own evil image. As they fade away, the Three tell Jack to prepare for a change that is coming, one precipitated by a death.
As the Werewolf and Brother Voodoo again fall through the void, Lt. Victor Northrup finds the demon pit and is immediately devoured by a serpent. Soon, Jack and Brother Voodoo reach the bottom of the pit where they discover an enormous black egg, which Jack recognizes as a trademark of Dr. Glitternight. Daniel's spirit passes through the surface of the egg, and Jack, using the strength of the Werewolf, breaks into it, the cracks sealing up behind him.
Within, Daniel has speech and substance, while Jack becomes human. They explore the cavernous interior until they come upon several zuvembies, lying inert and acting as templates for the false copies. As a group of demons slither toward the pair, the Three Who Are All appear to Jack to tell him it is within his power to become the Werewolf at will, and to fully control him. He does so, but he and Brother Voodoo are quickly surrounded by the demons, as well as Dr. Glitternight and Topaz, whom the sorcerer has transformed into a vicious harpy.