An elderly horticulturist and Korean War veteran, Earl Stone, is facing financial ruin and is estranged from his family. When his daylily business becomes obsolete due to the rise of the internet, he inadvertently meets a man at his granddaughter's engagement party who offers him a job that requires only driving. Desperate for money, Earl accepts the job without knowing what it entails. He soon discovers that he's become a drug mule for a Mexican cartel, transporting large quantities of cocaine through Illinois. His success in eluding law enforcement attributed to his unassuming appearance and clean record leads to increasingly larger shipments.

As Earl's new venture begins to reward him with substantial financial gains, he uses the money to try and rebuild the bridges he's burned with his family over the years. All the while, he remains oblivious to the moral and legal implications of his actions. Meanwhile, a determined DEA agent is recruited to tackle the drug problem in the area. As Earl continues his illicit activities, the agent and his task force begin to close in on the cartel's operations, collecting clues and tightening the net around the mules and the drug lords behind the scenes. Unbeknownst to Earl, his late-life choices have placed him in the crosshairs of a dangerous and far-reaching drug enforcement investigation.