Why does Delano not see what is really going on even though he suspects that there is something wrong?

Benito Cereno presents several conflicting narratives. One is Delano telling of what he sees happening on the ship, the other is the story of what is really going on (which the reader only discovers at the end) and the third is the fake, or constructed story. Describe each of those stories and relate them to the larger issue of truth vs reality.