The Pugad Baboy residents go off on vacation to Dueñas in Iloilo. There, Bab introduces them to their host, Mang Danilo, a faith healer who had once cured Bab off his dependence on drugs. Their adventures soon go from the innocent (having their futures revealed by a fortune teller and getting served herbal tea in a beer house) to the macabre (a guest relations girl turns out to be a manananggal, a kapre asks Mang Dagul for a light and even the Sesame Street's Count von Count makes an appearance).
One night, supernatural beings make a determined siege upon the house occupied by the Pugad Baboy gang. Polgas comes to the rescue in the guise of Growlsbuster (a spoof of the Ghostbusters). Using garlic in various forms (pills, powder and even garlic-flavored pizza), Growlsbuster repels the attack. The demons, witches and vampires retreat, but Polgas isn't content; he continues bombarding with garlic until the whole house began to smell like an Italian's breath.
In the confusion, the gang mislook the fact that one of their number is left outside the house, unprotected by the garlic - Pao is exchanging gossip with a "white lady" (a female ghost). Werewolves then take him captive, mistaking him for a pregnant woman. Perceiving that it is beyond Growlsbuster's skills to mount a rescue attempt, Polgas retires the guise and takes on his Wisedog persona. As Wisedog, he disguises himself further to resemble a werewolf, becoming Weredog.
Weredog infiltrates the werewolves' lair in the mountains, discovering that Devlino, the king of the supernatural beings, intends to sacrifice Pao at the stroke of midnight and that the "fetus" in his "womb" will become the main ingredient for the super-special batchoy the werewolves are preparing. Devlino, however, sees through Weredog's disguise, setting the werewolves on him. Weredog holds his own, but eventually succumbs when he accidentally smells the armpit of one of the werewolves; his excellent sense of smell is overpowered and he is rendered unconscious. Mang Danilo arrives in the nick of time and rescues Polgas. Both return to Dueñas.
Polgas recruits the Pugad Baboy residents in order to rescue Pao. They go to confession and made slingshots using barbecue sticks and silverware as ammo. Polgas refills his "garapata gun" with holy water from the church font (werewolves are immune to fleas since they are canine themselves). Eight minutes before midnight, the rescue squad attack the supernatural beings' lair. Every demon and werewolf hit by stick and silverware disappears into smoky nothingness, while to the demons' surprise, the Pugad Baboy gang seem unaffected by claw or fang. Four minutes to midnight, Devlino runs away with Pao; Polgas gives chase but is temporarily delayed by zombies blocking his way. Using the jawbone of a horse as a boomerang, Polgas destroys the sacrificial knife wielded by Devlino, who unmasked, turns out to be no other than their host, Mang Danilo.
Lady Lucy (Lucifer) appears, revealing that he/she is the source of Devlino/Danilo's power. As punishment for his failure as the king of evil in Iloilo, Lady Lucy turns him into a poisonous mushroom. Lady Lucy then disappears. The Pugad Baboy residents then return to Dueñas, having successfully rescued Pao.