In a quiet Ohio town, Maggie, a teenager new to the area, befriends a group of high school students seeking to indulge in underage drinking. Eager to fit in and looking for some excitement, the group struggles to buy alcohol until they meet Sue Ann, a middle-aged veterinary assistant who not only buys them liquor but also offers her basement as a place for them to party away from prying eyes. Dubbed "Ma" by the teenagers, Sue Ann's basement quickly becomes the center of their social life, a hidden haven where they believe they can escape the limitations of their age and enjoy their youth without consequence.

However, as the group spends more time at Sue Ann's home, her hospitality begins to morph into obsession. Unsettling incidents hint that her motivations might not be as benign as they first appeared. The teenagers commence to notice strange behaviors and rules, signaling that Sue Ann has a twisted past tied to the town. Despite their initial enjoyment, it becomes clear that Ma's house is not the carefree paradise they thought it was. The deeper they are drawn into Sue Ann's world, the more they realize that their host's intentions are far from simple generosity, setting the stage for a chilling unraveling of sinister secrets and intentions.