At the end of the trial, Babo is executed and his head placed on a pole. Cereno falls into a deep misery, and a few months later he dies—he did indeed "follow his leader."
The riddle is finally revealed: the slaves were in control all the time. Everything Delano witnessed makes sense, upon reflection. Most subtle was Cereno's method of hiding his nervousness: he made himself appear to be mentally ill or sick, and prone to faint, and he used those fainting spells to distract Delano whenever he became worried that Delano was in danger of discovering the truth. If Delano found out that the slaves were running things, Babo would have them both killed. While Delano was worried that Cereno was plotting to kill him, Cereno was in fact preserving the other captain's life through his strange behavior. It is this concern for the safety of Delano and his crew that finally sends Cereno over the edge and into Delano's boat. He knows that Babo is planning to capture Delano's ship while his men are on shore, and this drives him to escape despite Babo's threat.
The deposition itself is interesting primarily for the way it explains all the strange things Delano witnessed while on board. But in this last section of "Benito Cereno," the reader is forced to examine the story's treatment of blacks, and whether their revolt was justified. Certainly the deposition paints them in the worst light: the slaves murder dozens of men in their sleep, and Babo is a cold-blooded murderer who casually orders the death of Alexander Aranda. A slave revolt, of course, is the worst fear of all slave owners and traders. This one is particularly brutal and effective, thanks to their leader Babo.
Babo is a complex character. He is arguably more intelligent than either Cereno or Delano, because he has almost total control over Cereno and successfully fools Delano. It is sheer luck that Cereno survives his leap into the boat and Babo fails to kill him. Babo's performance as Cereno's servant is so convincing that Delano admires him on several occasions for his loyalty to his master, and even offers, half-jokingly, to buy him. When the story is re-read, there is a blatant irony in the relationship between Babo and Cereno. Cereno is the real servant, of course, and every time he reels and falls into Babo's embrace, it could be the embrace of death. Babo hovers over Cereno like Death himself, threatening to take his life should he make one wrong move. The shaving scene, where Babo accidentally nicks Cereno's throat, takes on a particularly sinister character. But it is unclear what Melville is trying to say by making Babo so intelligent. Is Babo intelligent, or is he just very cunning? Since Babo can speak and write Spanish, it is likely that he is quite intelligent. By having him outwit two white commanders, Melville is crediting Babo with considerable intelligence. But whether this is intended as proof that blacks are as smart as whites, or simply to make Babo into a formidable and frightening villain, is unclear. Much of Melville's fiction is written without such absolutes; the gray areas are intentional.
Probably the most significant fact at the end of the story is Cereno's inability to recover. Delano asks him what has cast such a "shadow" upon him, and Cereno responds "the Negro." This could mean many things. It could mean that Cereno's mind has been ruined by the terrible ordeal he has gone through. More symbolically, it could mean that Cereno realizes he is less intelligent than a black slave, so a "shadow" is now cast over his own skin, making him the "black."
This last interpretation may be supported by the last few lines of the story. Delano tells us that a few months after Babo was executed for his crimes, Cereno died and was buried in the same cemetery as Alexander Aranda, and therefore he truly "followed his leader." But this statement comes right after Delano describes the death of Babo, while Aranda is only mentioned very briefly in passing. So the reader can never be sure just who Cereno's "leader" really was—his friend Aranda, or Babo the black slave?