You knew it all along. You had a feeling months before, but you were unsure. Now you're certain.
Micah was the rat. Micah - that racist, selfish bastard was the rat the whole time. You had to tell Dutch immediately, you had to let him know he was the reason for all of this.
But as you tell Dutch, and the rest of the gang, you and Micah are now locked in a stand off. He has his two revolvers set on you, and you, your pistol set on him.
Both of you are bickering, trying to get Dutch on your sides. It boiled your blood that the man was lying through his teeth so easily - how did you not see it before?
"Now!" Dutch yells, pulling out his own two guns to point at the both of you. He slowly walks closer, his brows furrowed. "Who amongst you.. is with me, and who.. is betraying me?!"
Yet.. you can see him slowly walking toward Micah.