Les McConnell, posing as a gun salesman, is the front-man for the Stark Gang. He's gone into Sedalia, Missouri as the advanced scout for a bank heist. The gang rides in and robs the bank, killing the bank manager. They get away and later decide to hit the bank in Dodge, even though McConnell advises against messing with Marshal Dillon. The leader, Jim Stark, dismisses the warning and sets the gang's path toward Dodge. McConnell goes in ahead of the gang to check things out. The bank gets robbed and, as the gang is riding out of town, they run headlong into Matt and Festus. Some of the gang members are killed and one is severely wounded. Doc is kidnapped and taken along to tend him. Matt starts to put together a large posse to chase the gang down, but McConnell has other ideas.