Private investigator Sheba Shayne returns from Chicago to her hometown of Louisville, Kentucky, determined to confront the thugs trying to pressure her father, Andy Shayne, into dissolving or handing over the family insurance business. She teams up with her father’s loyal partner, Brick Williams, and the two rekindle an old romance as danger closes in around them.
Back home, Sheba is driving in her father’s car when a massive blast nearly finishes her off, a brutal reminder that someone is willing to go to extreme lengths to stop her. The attack shakes the town and intensifies her resolve to push forward with her investigation, even as the local police warn her to drop the case.
The pressure mounts when four gangsters ride into Andy’s office and open fire. Sheba fights back, killing three of them, but the clash leaves her father shot and killed in the crossfire. The killing cues a deeper investigation that leads Sheba to an apartment complex, where another volley of violence erupts. A tense chase pushes them into a nearby amusement park, where Sheba corners a gangster named Pilot and compels him to reveal a dangerous truth: the local gang is controlled by an insurance salesman known as Shark Merrill.
With new evidence in hand, Sheba joins a party aboard Shark’s yacht, only to be identified and captured by the criminals. The gang eliminates Pilot by tying him to a speedboat and dragging him mercilessly through the water. When they try the same fate on Sheba, she uses a hidden knife in her wetsuit to cut the rope and escape. Brick rallies the police to converge on the yacht, and a fierce gun battle erupts once more.
Shark tries to flee in a speedboat, but Sheba stays hot on his tail, pursuing him on a jet ski and killing him with a spear gun. The showdown marks a brutal end to Shark Merrill’s control over the operation, and Brick urges Sheba to consider a future together. Yet Sheba, with the stakes finally clear, decides to return to Chicago, while promising to come back to see Brick again since they are now bound as business partners.
