Describe the confrontation between Scruggs and Robicheaux in this section.

Harpo Scruggs enters Robicheaux's bait shop armed with a "blue-black .2 Ruger revolver with ivory grips" Scruggs, who has been shot, persuades Robicheaux drive him to Opelousas. On the way he tells Robicheaux that Archer Terrebonne paid Scruggs's partner to kill him. He also confesses to the murder of the two brothers at Atchafalaya Swamp.