Nothing much ever happens in Meridosa until now. A notorious outlaw Sergio Van Cleef is being kept in the jail for the night until Marshall Tucker can transport him to the train station to catch the 3:10 to Yuma. Mrs. Peacock, president of the Ladies Ethics Guild is none too happy about the arrangement, nor is she happy that the new Saloon "entertainer", Sadie Mae Harlow has not been run out of town. But while Sheriff John Ford keeps watch, the prisoner ends up dead in his cell. No one was around at the time or had access to the prisoner. With the help of Parson Graham and Doc Watson, the Sheriff must try to solve this case, if only for his own satisfaction.