Fletch by Gregory Mcdonald

In the mystery novel Fletch by Gregory Mcdonald, an investigative journalist named Irwin Maurice Fletcher goes undercover as a beach-dwelling addict to expose a drug trafficking ring. While on assignment, he is approached by a wealthy businessman, Alan Stanwyk, who offers him fifty thousand dollars to commit a murder—specifically, Stanwyk's own. As Fletch juggles his drug investigation and his alimony debts, he discovers that Stanwyk has fabricated a terminal cancer diagnosis and is leading a complex double life involving a secret mistress. Fletch eventually unmasks the local police chief as the drug kingpin and outmaneuvers Stanwyk’s deadly insurance fraud scheme. The story concludes with Fletch escaping to South America with millions of dollars in cash, having successfully solved both crimes.