Don Counsel, a New Yorker who is traveling through southern Florida, is being framed by Ernest Riever for a murder he did not commit. Riever is holding the real killer captive on his yacht while detectives are searching for Counsel. Pen Broome, who lives with her father (Henry James) on their rundown estate, tries to help Counsel out. Riever's men find Counsel and trap him in a ballast bulkhead, but Pen rescues him.