厄尔（克林特·伊斯特伍德 Clint Eastwood 饰）是一名独居的八旬老人，正在面临非常严峻的财务危机，他唯一的住所即将被拍卖用来抵扣债务，在这个节骨眼上，厄尔得到了一份司机的工作，但厄尔所要运送的却并非什么乘客，而是毒品。就这样，厄尔成为了墨西哥贩毒集团中的一员。 　　不得不承认，厄尔将这份工作完成的非常出色，出色到贩毒集团专门为他配备了对接人员。可就在厄尔的财务问题得到解决的同时，他的反常举动也遭到了美国缉毒局特工科林（布莱德利·库珀 Bradley Cooper 饰）的注意。如果继续在法律的边缘试探，厄尔就有可能锒铛入狱，但如果就此金盆洗手，知道太多秘密的厄尔亦有可能被毒枭灭口。Earl Stone is a 90-year-old horticulturist and Korean War veteran who is facing financial ruin and is estranged from his family. Desperate for money, he becomes a "mule" transporting cocaine through Illinois for a Mexican drug cartel. He becomes a sort of "Robin Hood" with his ill gotten money, renovating his VFW Post and paying for his gran-daughter's wedding. He makes peace with his ex wife before her death as the DEA and the cartel close in on him..