Brittney Havers, a South Florida high school senior, lives with her wealthy stepfather, Niles Dunlap, after her mother ran her car off the road in “Gator Alley” and was presumably eaten by alligators a year earlier. When Dunlap is killed in a private plane crash, his will calls for Brittney to receive a small stipend until she finishes college, after which she will receive only $ 25,000 a year for life from the estate. The rest of Dunlap’s assets, totaling $ 70 million, are to be left to a corporate trust, unless a blood heir can be found.
Brittney’s brash, relatively poor classmate Maya King suddenly claims to be Dunlap’s illegitimate daughter as the result of her mother’s extramarital affair. She is ordered by a judge to submit to a DNA test, the result of which proves she is Dunlap’s child.
At the Dunlap home, Brittney hears a noise on her way to the wine cellar but it turns out to just be rats. Suddenly Maya appears and the girls reveal they are lovers before being joined by Dr. Julian Haynes, who had arranged the DNA test. The trio are in cahoots, running a scam to secure and share Dunlap’s fortune.
Insurance investigator Terence Bridge, investigating the circumstances of the plane crash, finds out from Dunlap’s medical records that Dunlap had scarlet fever as a child, one of the side effects of which can be sterility, and asks Dr. Haynes how Dunlap could have fathered a child. Dr. Haynes gets nervous about the plot unraveling and contacts Maya. He agrees to meet her and Brittney that night at the docks, where Maya shoots him. The two girls dispose of his body in Gator Alley.