After being diagnosed with a fatal brain tumor, private investigator Frank Armstrong is hired by local crime lord Gibson to locate his missing daughter, Evelyn. Frank accepts, but his search is complicated by the seizures, pain, and disorientation caused by his condition. With some help from Jimmy, a police detective and friend, Frank finds Evelyn. Her boyfriend has been killed, and she murders one of Gibson's henchman who had been following Frank. Frank persuades Evelyn to let him protect her from her father.
Because of his illness, Frank sometimes confuses Evelyn for his dead wife, who she resembles. The two go to Jimmy for help, only to learn Jimmy works for Gibson, and is partly responsible for the death of Frank's wife. Jimmy apologizes, and explains the help he has given Frank over the years was partly out of guilt. Evelyn reveals Gibson is looking for her because she stole money from him, and she killed her own boyfriend. Frank contacts friends from the FBI, and arranges a meeting with Gibson to finish his contract.
At the meeting, Gibson and Frank are fatally shot, and Jimmy is wounded. Before he dies, Frank falsely explains the situation to the FBI, who had not yet arrived. Jimmy's misdeeds are not revealed and he appears to be the hero. Evelyn's theft is also concealed, and she is allowed to leave with the money and begin a new life.