Pen Broome, who lives with her father on their rundown estate in southern Florida, helps Don Counsell hide from detectives who seek him for the murder of his business partner. Don is being framed by Ernest Riever, who holds the real murderer, Spike Talley, captive aboard his yacht. Don is finally captured by Riever and placed in a ballast bulkhead into which water is allowed to flow. Pen finds the yacht with the aid of a Seminole man and offers Riever marriage in return for Don's life just as Spike breaks in. Fearing a double-cross, he denounces Riever for the murder. Detectives enter and rescue Don, while Riever shoots himself.