Gumapang Ka sa Lusak revolves around the lives of engaged sweethearts Rachel (Jennylyn Mercado), an aspiring young actress, and Levi (Dennis Trillo), a poor, happy-go-lucky guy. In the town of San Felipe, Rachel's beauty stands out. She becomes the object of desire for many men, including their own mayor, Edmundo Guatlo (Al Tantay). With a fervent desire to have her, Mayor Guatlo will use all his power to make Rachel his mistress. Rachel rejects all the gifts and favors offered by the mayor. However, she will fall into the wicked mayor's trap after a series of misfortunes happen to her loved ones, including her fiancé Levi, who gets imprisoned due to an illegal activity. Although the mayor's wife, Rowena (Sandy Andolong), is aware of her husband's infidelity, she goes along with it as long as the affair doesn't affect her comfortable and powerful position in the society. However, things will make a sudden turn when Mayor Guatlo's secret is exposed to the public. It is a secret that ...